Patent Description:
The treatment of open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by means of applying negative pressure to the site of the wound is well known in the art. Negative pressure wound therapy (NPWT) systems currently known in the art commonly involve placing a cover that is impermeable or semi-permeable to fluids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of negative pressure (such as a vacuum pump) to the cover in a manner so that negative pressure is created and maintained under the cover. It is believed that such negative pressures promote wound healing by facilitating the formation of granulation tissue at the wound site and assisting the body's normal inflammatory process while simultaneously removing excess fluid, which may contain adverse cytokines and/or bacteria. However, further improvements in NPWT are needed to fully realize the benefits of treatment.

Many different types of wound dressings are known for aiding in NPWT systems. These different types of wound dressings include many different types of materials and layers, for example, gauze, pads, foam pads or multi-layer wound dressings. One example of a multi-layer wound dressing is the PICO dressing, available from Smith & Nephew, which includes a superabsorbent layer beneath a backing layer to provide a canister-less system for treating a wound with NPWT. The wound dressing may be sealed to a suction port providing connection to a length of tubing, which may be used to pump fluid out of the dressing and/or to transmit negative pressure from a pump to the wound dressing.

Prior art dressings for use in negative pressure such as those described above have included a negative pressure source located in a remote location from the wound dressing. Negative pressure sources located remote from the wound dressing have to be held by or attached to the user or other pump support mechanism. Additionally, a tubing or connector is required to connect the remote negative pressure source to the wound dressing. The remote pump and tubing can be cumbersome and difficult to hide in or attach to patient clothing. Depending on the location of the wound dressing, it can be difficult to comfortably and conveniently position the remote pump and tubing. When used, wound exudate may soak into the dressing, and the moisture from the wound has made it difficult to incorporate electronic components into the dressing.

Relevant prior art can be found in <CIT>.

Embodiments of the present disclosure relate to apparatuses and methods (not claimed) for wound treatment. Some of the wound treatment apparatuses described herein comprise a negative pressure source or a pump system for providing negative pressure to a wound. Wound treatment apparatuses may also comprise wound dressings that may be used in combination with the negative pressure sources and pump assemblies described herein. In some embodiments, a negative pressure source is incorporated into a wound dressing apparatus so that the wound dressing and the negative pressure source are part of an integral or integrated wound dressing structure that applies the wound dressing and the negative pressure source simultaneously to a patient's wound. The negative pressure source and/or electronic components may be positioned between a wound contact layer and a cover layer of the wound dressing. A component may be used to prevent wound exudate from contacting the inlet of the negative pressure source. These and other embodiments as described herein are directed to overcoming particular challenges involved with incorporating a negative pressure source and/or electronic components into a wound dressing.

In some aspects, a wound dressing apparatus comprises a wound dressing configured to be positioned over a wound site, the wound dressing comprising a wound contact layer configured to be positioned in contact with a wound, a first area and a second area positioned adjacent to the first area, wherein the first area comprises an absorbent material and the second area is configured to receive a negative pressure source, and a cover layer configured to cover and form a seal over the wound contact layer, the first area, and the second area, a negative pressure source disposed on or positioned within the second area of the wound dressing, the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and a component in fluid communication with the inlet, the component defining a plurality of flow paths between an interior of the wound dressing and the inlet such that occlusion of the inlet is inhibited, and wherein the component is in fluid communication with the absorbent material and configured to inhibit flow of wound exudate from the wound site into the inlet.

The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. Each of the features described in the following paragraphs may also be part of another embodiment that does not necessarily include all of the features of the previous paragraph. The component can comprise a hydrophobic material configured to repel wound exudate. The component can comprise a material having a pore size configured to resist ingress of wound exudate due to capillary action. The component can comprise one or more porous polymer molded components. The polymer comprising the one or more porous polymer molded components can be hydrophobic and can have a pore size in the range of approximately <NUM> microns to approximately <NUM> microns. The pore size can be approximately <NUM> microns. The polymer comprising the one or more porous polymer molded components can be hydrophobic and can have a pore size in the range of approximately <NUM> microns to approximately <NUM> microns. The pore size can be approximately <NUM> microns.

The polymer can be POREX® or PORVAIR®. The polymer can be one of hydrophobic polyethylene or hydrophobic polypropylene. Each of the one or more porous polymer molded components can be configured to increase the contact area between the pump inlet and the interior of the wound dressing. The one or more porous polymer components have a three-dimensional shape. For example, the one or more porous polymer components can be crescent-shaped, thimble-shaped, or cuboid or generally cuboid shaped. The one or more porous polymer components can also have curved or beveled corners and/or edges. The one or more porous polymer components can be configured to attach to at least one of the inlet and an end of a tubular extension in fluid communication with the inlet and the interior of the wound dressing.

The component can comprise one or more micro porous membranes attached to the inlet. The wound dressing apparatus can comprise a spacer material disposed within the membrane, the spacer material configured to inhibit the membrane from collapsing. The micro porous membrane can comprise Versapore having a <NUM> micron pore size (Pall). The component can comprise one or more lengths of fine bore tubing defining a plurality of holes along their lengths. The one or more lengths of fine bore tubing can form one or more loops between the inlet and the wound dressing. The one or more lengths of fine bore tubing can extend from the inlet to one or more different points in the wound dressing. The negative pressure source can be a micro pump. The wound dressing apparatus can comprise a controller configured to control the operation of the micro pump to apply negative pressure to the wound site. The absorbent material can be configured to absorb wound exudate. The component can be attached to the inlet. The component can be fitted to the inlet.

In the claimed embodiment, a wound dressing apparatus comprises a wound dressing configured to be positioned over a wound site, a negative pressure source disposed on or positioned within the wound dressing, the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and a porous polymer component fitted to the inlet of the negative pressure source and in fluid communication with the inlet, the porous polymer component comprising a three-dimensional body defining a plurality of flow paths between an interior of the wound dressing and the inlet such that occlusion of the inlet is inhibited. Additionally, the negative pressure source is a pump and the porous polymer component is provided on the inlet of the pump, wherein the porous polymer component comprises a port that is shaped to receive a portion of the pump inlet.

The porous polymer component can comprise a hydrophobic material configured to repel wound exudate. The porous polymer component can have a pore size in the range of approximately <NUM> microns to approximately <NUM> microns. The pore size can be approximately <NUM> microns. The porous polymer component can have a pore size in the range of approximately <NUM> microns to approximately <NUM> microns. The pore size can be approximately <NUM> microns. The polymer can be PORVAIR Vyon®. The porous polymer component can be crescent-shaped, thimble-shaped, or cuboid or generally cuboid shaped. The porous polymer component can also have curved or beveled corners and/or edges.

Any of the features, components, or details of any of the arrangements or embodiments disclosed in this application, including without limitation any of the pump embodiments and any of the negative pressure wound therapy embodiments disclosed below, are interchangeably combinable with any other features, components, or details of any of the arrangements or embodiments disclosed herein to form new arrangements and embodiments.

Embodiments disclosed herein relate to apparatuses and methods of treating a wound with reduced pressure, including a source of negative pressure and wound dressing components and apparatuses. The apparatuses and components including the wound overlay and packing materials, if any, are sometimes collectively referred to herein as dressings.

It will be appreciated that throughout this specification reference is made to a wound. It is to be understood that the term wound is to be broadly construed and encompasses open and closed wounds in which skin is torn, cut or punctured or where trauma causes a contusion, or any other superficial or other conditions or imperfections on the skin of a patient or otherwise that benefit from reduced pressure treatment. A wound is thus broadly defined as any damaged region of tissue where fluid may or may not be produced. Examples of such wounds include, but are not limited to, abdominal wounds or other large or incisional wounds, either as a result of surgery, trauma, sterniotomies, fasciotomies, or other conditions, dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, bums, diabetic ulcers, pressure ulcers, stoma, surgical wounds, trauma and venous ulcers or the like.

It will be understood that embodiments of the present disclosure are generally applicable to use in topical negative pressure ("TNP") therapy systems. Briefly, negative pressure wound therapy assists in the closure and healing of many forms of "hard to heal" wounds by reducing tissue oedema; encouraging blood flow and granular tissue formation; removing excess exudate and may reduce bacterial load (and thus infection risk). In addition, the therapy allows for less disturbance of a wound leading to more rapid healing. TNP therapy systems may also assist on the healing of surgically closed wounds by removing fluid and by helping to stabilize the tissue in the apposed position of closure. A further beneficial use of TNP therapy can be found in grafts and flaps where removal of excess fluid is important and close proximity of the graft to tissue is required in order to ensure tissue viability.

As is used herein, reduced or negative pressure levels, such as -X mmHg, represent pressure levels relative to normal ambient atmospheric pressure, which can correspond to <NUM> mmHg (or <NUM> atm, <NUM> inHg, <NUM> kPa, <NUM> psi, etc.). Accordingly, a negative pressure value of -X mmHg reflects absolute pressure that is X mmHg below <NUM> mmHg or, in other words, an absolute pressure of (<NUM>-X) mmHg. In addition, negative pressure that is "less" or "smaller" than X mmHg corresponds to pressure that is closer to atmospheric pressure (e.g.,-<NUM> mmHg is less than -<NUM> mmHg). Negative pressure that is "more" or "greater" than -X mmHg corresponds to pressure that is further from atmospheric pressure (e.g., -<NUM> mmHg is more than -<NUM> mmHg). In some embodiments, local ambient atmospheric pressure is used as a reference point, and such local atmospheric pressure may not necessarily be, for example, <NUM> mmHg.

The negative pressure range for some embodiments of the present disclosure can be approximately -<NUM> mmHg, or between about -<NUM> mmHg and -<NUM> mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, which can be <NUM> mmHg. Thus, -<NUM> mmHg would be about <NUM> mmHg in practical terms. In some embodiments, the pressure range can be between about -<NUM> mmHg and -<NUM> mmHg. Alternatively, a pressure range of up to -<NUM> mmHg, up to -<NUM> mmHg or over -<NUM> mmHg can be used. Also, in other embodiments, a pressure range of below -<NUM> mmHg can be used. Alternatively, a pressure range of over approximately -<NUM> mmHg, or even -<NUM> mmHg, can be supplied by the negative pressure apparatus.

In some embodiments of wound closure devices described herein, increased wound contraction can lead to increased tissue expansion in the surrounding wound tissue. This effect may be increased by varying the force applied to the tissue, for example by varying the negative pressure applied to the wound over time, possibly in conjunction with increased tensile forces applied to the wound via embodiments of the wound closure devices. In some embodiments, negative pressure may be varied over time for example using a sinusoidal wave, square wave, and/or in synchronization with one or more patient physiological indices (e.g., heartbeat). Examples of such applications where additional disclosure relating to the preceding may be found include <CIT>; and <CIT>.

International Application <CIT>, and published as <CIT>, is an application, hereby incorporated and considered to be part of this specification, that is directed to embodiments, methods of manufacture, and wound dressing components and wound treatment apparatuses that may be used in combination or in addition to the embodiments described herein. Additionally, embodiments of the wound dressings, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in <CIT>, titled "APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY," International Application No. <CIT>, titled "APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY," and published as <CIT>, <CIT>, published as <CIT>, titled "WOUND DRESSING AND METHOD OF TREATMENT," <CIT>, published as <CIT>, titled "WOUND DRESSING AND METHOD OF TREATMENT," <CIT>, <CIT>, titled "WOUND DRESSING AND METHOD OF TREATMENT. " Embodiments of the wound dressings, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in <CIT>, published as <CIT>, titled "WOUND DRESSING AND METHOD OF USE," including further details relating to embodiments of wound dressings, the wound dressing components and principles, and the materials used for the wound dressings. Additionally, the present application is related to <CIT>, titled "REDUCED PRESSURE APPARATUSES AND METHODS, the subject matter of which is considered to be part of this application and is included in the Appendix below.

<FIG> illustrates an embodiment of a TNP wound treatment including a wound dressing <NUM> in combination with a pump <NUM>. As stated above, the wound dressing <NUM> can be any wound dressing embodiment disclosed herein or have any combination of features of any number of wound dressing embodiments disclosed herein. Here, the dressing <NUM> may be placed over a wound, and a conduit <NUM> may then be connected to a port <NUM>, although in some embodiments the dressing <NUM> may be provided with at least a portion of the conduit <NUM> preattached to the port <NUM>. Preferably, the dressing <NUM> is provided as a single article with all wound dressing elements (including the port <NUM>) pre-attached and integrated into a single unit. The wound dressing <NUM> may then be connected, via the conduit <NUM>, to a source of negative pressure such as the pump <NUM>. The pump <NUM> can be miniaturized and portable, although larger conventional pumps may also be used with the dressing <NUM>. In some embodiments, the pump <NUM> may be attached or mounted onto or adjacent the dressing <NUM>. A connector <NUM> may also be provided so as to permit the conduit <NUM> leading to the wound dressing <NUM> to be disconnected from the pump, which may be useful for example during dressing changes.

In some embodiments, a source of negative pressure (such as a pump) and some or all other components of the TNP system, such as power source(s), sensor(s), connector(s), user interface component(s) (such as button(s), switch(es), speaker(s), screen(s), etc.) and the like, can be integral with the wound dressing. As is illustrated in <FIG>, the source of negative pressure and battery can be included within the integrated dressing <NUM>. Although <FIG> illustrates the source of negative pressure and battery <NUM> placed on top of the dressing layer <NUM> (such as an absorbent layer), the source of negative pressure and one or more components can be incorporated into the dressing differently. The source of negative pressure and the one or more components need not all be incorporated into the dressing in the same manner. For example, a pressure sensor can be positioned below (or closer to the wound) the layer <NUM> while the source of negative pressure can be positioned on top of the layer <NUM>. The integrated dressing <NUM> illustrated in <FIG> includes a cover layer <NUM> that can secure the dressing to skin surrounding the wound. The cover layer <NUM> can be formed of substantially fluid impermeable material, such as film (e.g., plastic film). The cover layer can include an adhesive for securing the dressing to the surrounding skin or wound contact layer.

In some embodiments, the dressing can include the power source and other components, such as electronics, on and/or incorporated into the dressing and can utilize a wound contact layer and a first spacer layer within the dressing. The wound contact layer can be in contact with the wound. The wound contact layer can include an adhesive on the patient facing side for securing the dressing to the skin surrounding the wound or on the top side for securing the wound contact layer to a cover layer or other layer of the dressing. In operation, the wound contact layer can provide unidirectional flow so as to facilitate removal of exudate from the wound while blocking or substantially preventing exudate from returning to the wound. The first spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. Further, an absorbent layer (such as layer <NUM>) for absorbing and retaining exudate aspirated from the wound can be utilized. In some embodiments, the absorbent includes a shaped form of a superabsorber layer with recesses or compartments for the pump, electronics, and accompanying components. These layers can be covered with one or more layers of a film or cover layer (or a first cover layer). The first cover layer can include a filter set that can be positioned within one of the recesses. The filter can align with one of the at least one recesses of the absorbent layer, and the filter can include hydrophobic material to protect the pump and/or other components from liquid exudates. The filter can block fluids while permitting gases to pass through. Optionally, one or more of the pump, electronics, switch and battery can be positioned on top of the first cover layer as illustrated in <FIG>. Another section of spacer, a second spacer, can be positioned above and/or surrounding the pump. In some embodiments, the second spacer can be smaller than the first spacer used above the wound contact layer. A section of top film or cover layer (or a second cover layer) is positioned over the top of the second spacer with a second filter associated with or positioned within the second cover layer. In some embodiments, the first and second cover layer can be made of the same material. In some embodiments, the first and second cover layers can be made of different material.

In some embodiments, the pump and/or other electronic components can be configured to be positioned adjacent to or next to the absorbent and/or transmission layers so that the pump and/or other electronic components are still part of a single apparatus to be applied to a patient with the pump and/or other electronics positioned away from the wound site. <FIG> illustrates a wound dressing incorporating the source of negative pressure and/or other electronic components within the wound dressing. <FIG> illustrates a wound dressing <NUM> with the pump and/or other electronics positioned away from the wound site. The wound dressing can include an electronics area <NUM>, <NUM> and an absorbent area <NUM>, <NUM>. The dressing can comprise a wound contact layer <NUM> (not shown in <FIG>) and a moisture vapor permeable film or cover layer <NUM>, <NUM> positioned above the contact layer and other layers of the dressing. The wound dressing layers and components of the electronics area as well as the absorbent area can be covered by one continuous cover layer <NUM>, <NUM> as shown in <FIG>.

The dressing can comprise a wound contact layer <NUM>, a spacer layer <NUM>, an absorbent layer <NUM>, <NUM>, a moisture vapor permeable film or cover layer <NUM>, <NUM> positioned above the wound contact layer, spacer layer, absorbent layer, or other layers of the dressing. The wound contact layer can be configured to be in contact with the wound. The wound contact layer can include an adhesive on the patient facing side for securing the dressing to the surrounding skin or on the top side for securing the wound contact layer to a cover layer or other layer of the dressing. In operation, the wound contact layer can be configured to provide unidirectional flow so as to facilitate removal of exudate from the wound while blocking or substantially preventing exudate from returning to the wound.

The wound contact layer <NUM> can be a polyurethane layer or polyethylene layer or other flexible layer which is perforated, for example via a hot pin process, laser ablation process, ultrasound process or in some other way or otherwise made permeable to liquid and gas. The wound contact layer <NUM> has a lower surface and an upper surface. The perforations preferably comprise through holes in the wound contact layer <NUM> which enable fluid to flow through the layer <NUM>. The wound contact layer <NUM> helps prevent tissue ingrowth into the other material of the wound dressing. Preferably, the perforations are small enough to meet this requirement while still allowing fluid to flow therethrough. For example, perforations formed as slits or holes having a size ranging from <NUM> to <NUM> are considered small enough to help prevent tissue ingrowth into the wound dressing while allowing wound exudate to flow into the dressing. In some configurations, the wound contact layer <NUM> may help maintain the integrity of the entire dressing <NUM>, <NUM> while also creating an air tight seal around the absorbent pad in order to maintain negative pressure at the wound.

Some embodiments of the wound contact layer <NUM> may also act as a carrier for an optional lower and upper adhesive layer (not shown). For example, a lower pressure sensitive adhesive may be provided on the lower surface of the wound dressing <NUM>, <NUM> whilst an upper pressure sensitive adhesive layer may be provided on the upper surface of the wound contact layer. The pressure sensitive adhesive, which may be a silicone, hot melt, hydrocolloid or acrylic based adhesive or other such adhesives, may be formed on both sides or optionally on a selected one or none of the sides of the wound contact layer. When a lower pressure sensitive adhesive layer is utilized it may be helpful to adhere the wound dressing <NUM>, <NUM> to the skin around a wound site. In some embodiments, the wound contact layer may comprise perforated polyurethane film. The lower surface of the film may be provided with a silicone pressure sensitive adhesive and the upper surface may be provided with an acrylic pressure sensitive adhesive, which may help the dressing maintain its integrity. In some embodiments, a polyurethane film layer may be provided with an adhesive layer on both its upper surface and lower surface, and all three layers may be perforated together.

A layer <NUM> of porous material can be located above the wound contact layer <NUM>. As used herein, the terms porous material, spacer, and/or transmission layer can be used interchangeably to refer to the layer of material in the dressing configured to distribute negative pressure throughout the wound area. This porous layer, or transmission layer, <NUM> allows transmission of fluid including liquid and gas away from a wound site into upper layers of the wound dressing. In particular, the transmission layer <NUM> preferably ensures that an open air channel can be maintained to communicate negative pressure over the wound area even when the absorbent layer has absorbed substantial amounts of exudates. The layer <NUM> should preferably remain open under the typical pressures that will be applied during negative pressure wound therapy as described above, so that the whole wound site sees an equalized negative pressure. The layer <NUM> may be formed of a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (for example Baltex <NUM> weft knitted polyester) or a non-woven fabric could be used.

The spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. In some embodiments, the spacer layer can be formed at least partially from a three-dimensional (3D) fabric.

In some embodiments, the transmission layer <NUM> comprises a 3D polyester spacer fabric layer including a top layer (that is to say, a layer distal from the wound-bed in use) which is a <NUM>/<NUM> textured polyester, and a bottom layer (that is to say, a layer which lies proximate to the wound bed in use) which is a <NUM> denier flat polyester and a third layer formed sandwiched between these two layers which is a region defined by a knitted polyester viscose, cellulose or the like monofilament fiber. Other materials and other linear mass densities of fiber could of course be used.

Whilst reference is made throughout this disclosure to a monofilament fiber it will be appreciated that a multistrand alternative could of course be utilized. The top spacer fabric thus has more filaments in a yarn used to form it than the number of filaments making up the yarn used to form the bottom spacer fabric layer.

This differential between filament counts in the spaced apart layers helps control moisture flow across the transmission layer. Particularly, by having a filament count greater in the top layer, that is to say, the top layer is made from a yarn having more filaments than the yarn used in the bottom layer, liquid tends to be wicked along the top layer more than the bottom layer. In use, this differential tends to draw liquid away from the wound bed and into a central region of the dressing where the absorbent layer <NUM>,<NUM> helps lock the liquid away or itself wicks the liquid onwards towards the cover layer <NUM>, <NUM> where it can be transpired.

Preferably, to improve the liquid flow across the transmission layer <NUM> (that is to say perpendicular to the channel region formed between the top and bottom spacer layers, the 3D fabric may be treated with a dry cleaning agent (such as, but not limited to, Perchloro Ethylene) to help remove any manufacturing products such as mineral oils, fats or waxes used previously which might interfere with the hydrophilic capabilities of the transmission layer. In some embodiments, an additional manufacturing step can subsequently be carried in which the 3D spacer fabric is washed in a hydrophilic agent (such as, but not limited to, Feran Ice <NUM>/l available from the Rudolph Group). This process step helps ensure that the surface tension on the materials is so low that liquid such as water can enter the fabric as soon as it contacts the 3D knit fabric. This also aids in controlling the flow of the liquid insult component of any exudates.

Further, an absorbent layer (such as layer <NUM>) for absorbing and retaining exudate aspirated from the wound can be utilized. In some embodiments, a superabsorbent material can be used in the absorbent layer <NUM>. In some embodiments, the absorbent includes a shaped form of a superabsorber layer.

A layer <NUM>, <NUM> of absorbent material is provided above the transmission layer <NUM>. The absorbent material, which comprise a foam or non-woven natural or synthetic material, and which may optionally comprise a super-absorbent material, forms a reservoir for fluid, particularly liquid, removed from the wound site. In some embodiments, the layer <NUM> may also aid in drawing fluids towards the backing layer <NUM>, <NUM>.

The material of the absorbent layer <NUM>, <NUM> may also prevent liquid collected in the wound dressing from flowing freely within the dressing, and preferably acts so as to contain any liquid collected within the dressing. The absorbent layer <NUM>, <NUM> also helps distribute fluid throughout the layer via a wicking action so that fluid is drawn from the wound site and stored throughout the absorbent layer. This helps prevent agglomeration in areas of the absorbent layer. The capacity of the absorbent material must be sufficient to manage the exudates flow rate of a wound when negative pressure is applied. Since in use the absorbent layer experiences negative pressures the material of the absorbent layer is chosen to absorb liquid under such circumstances. A number of materials exist that are able to absorb liquid when under negative pressure, for example superabsorber material. The absorbent layer <NUM>, <NUM> may typically be manufactured from ALLEVYN™ foam, Freudenberg <NUM>-<NUM>-<NUM> or Chem-Posite™11C-<NUM>. In some embodiments, the absorbent layer <NUM>, <NUM> may comprise a composite comprising superabsorbent powder, fibrous material such as cellulose, and bonding fibers. In a preferred embodiment, the composite is an airlaid, thermally-bonded composite.

In some embodiments, the absorbent layer <NUM>, <NUM> is a layer of non-woven cellulose fibers having super-absorbent material in the form of dry particles dispersed throughout.

The wound dressing layers of the electronics area and the absorbent layer can be covered by one continuous cover layer or backing layer <NUM>. As used herein, the terms cover layer and/or backing layer can be used interchangeably to refer to the layer of material in the dressing configured to cover the underlying dressing layers and seal to the wound contact layer and/or the skin surrounding the wound. In some embodiments, the cover layer can include a moisture vapor permeable material that prevents liquid exudate removed from the wound and other liquids from passing through, while allowing gases through.

The backing layer <NUM>, <NUM> is preferably gas impermeable, but moisture vapor permeable, and can extend across the width of the wound dressing <NUM>. The backing layer <NUM>, <NUM>, which may for example be a polyurethane film (for example, Elastollan SP9109) having a pressure sensitive adhesive on one side, is impermeable to gas and this layer thus operates to cover the wound and to seal a wound cavity over which the wound dressing is placed. In this way, an effective chamber is made between the backing layer <NUM>, <NUM> and a wound site where a negative pressure can be established. The backing layer <NUM>, <NUM> is preferably sealed to the wound contact layer <NUM> in a border region around the circumference of the dressing, ensuring that no air is drawn in through the border area, for example via adhesive or welding techniques. The backing layer <NUM>, <NUM> protects the wound from external bacterial contamination (bacterial barrier) and allows liquid from wound exudates to be transferred through the layer and evaporated from the film outer surface. The backing layer <NUM>, <NUM> preferably comprises two layers; a polyurethane film and an adhesive pattern spread onto the film. The polyurethane film is preferably moisture vapor permeable and may be manufactured from a material that has an increased water transmission rate when wet. In some embodiments, the moisture vapor permeability of the backing layer increases when the backing layer becomes wet. The moisture vapor permeability of the wet backing layer may be up to about ten times more than the moisture vapor permeability of the dry backing layer.

The electronics area <NUM> can include a source of negative pressure (such as a pump) and some or all other components of the TNP system, such as power source(s), sensor(s), connector(s), user interface component(s) (such as button(s), switch(es), speaker(s), screen(s), etc.) and the like, that can be integral with the wound dressing. For example, the electronics area <NUM> can include a button or switch <NUM> as shown in <FIG>. The button or switch <NUM> can be used for operating the pump (e.g., turning the pump on/off).

The absorbent area <NUM> can include an absorbent material <NUM> and can be positioned over the wound site. The electronics area <NUM> can be positioned away from the wound site, such as by being located off to the side from the absorbent area <NUM>. The electronics area <NUM> can be positioned adjacent to and in fluid communication with the absorbent area <NUM> as shown in <FIG>. In some embodiments, each of the electronics area <NUM> and absorbent area <NUM> may be rectangular in shape and positioned adjacent to one another.

In some embodiments, additional layers of dressing material can be included in the electronics area <NUM>, the absorbent area <NUM>, or both areas. In some embodiments, the dressing can comprise one or more spacer layers and/or one or more absorbent layer positioned above the wound contact layer <NUM> and below the cover layer <NUM>, <NUM> of the dressing.

<FIG> is a side cross-sectional view of a wound dressing system <NUM>, according to some embodiments. As shown in <FIG>, the wound dressing system <NUM> can include a wound dressing <NUM> with one or more embedded (also referred to as integrated) electronic components <NUM>. The wound dressing <NUM> can include an absorbent area <NUM> and an electronics area <NUM>. In some embodiments, the electronic components <NUM> can be positioned within the wound dressing <NUM> in the electronics area <NUM>, although it should be appreciated that the electronic components <NUM> can be integrated with the wound dressing <NUM> in any suitable arrangement (e.g., disposed on and/or positioned within the wound dressing <NUM>, among other arrangements). The electronic components <NUM> can optionally include a pump <NUM>, a power source, a controller, and/or an electronics package, although any suitable electronic component is appreciated. The pump <NUM> can be in fluidic communication with one or more regions of the wound dressing <NUM>, such as, for example, the absorbent area <NUM> of the dressing. The absorbent area <NUM> and the electronics area <NUM> of the wound dressing <NUM> can have any suitable arrangement. For example, <FIG> illustrates an embodiment of the wound dressing <NUM> in which the electronics area <NUM> is offset from the absorbent area <NUM>.

As shown in <FIG>, the wound dressing <NUM> can include a wound contact layer <NUM> and a moisture vapor permeable film or cover layer <NUM> that encloses one or both of the absorbent area <NUM> and the electronics area <NUM>. The cover layer <NUM> can seal at the perimeter of the cover layer <NUM> to the wound contact layer <NUM> at the perimeter of the wound contact layer. In some embodiments, the dressing can optionally include an upper spacer layer or first spacer layer <NUM> that includes a continuous layer of spacer material positioned below the cover layer <NUM> and above the layers of the absorbent area and the layers of the electronics area. The continuous layer of spacer material or upper spacer layer <NUM> can enable an air pathway between the two areas of the dressing.

The absorbent area <NUM> of the dressing can include a second spacer layer <NUM> or lower spacer layer and an absorbent layer <NUM> positioned above the wound contact layer <NUM>. The second spacer layer <NUM> can allow for an open air path over the wound site. The absorbent layer <NUM> can include a super absorber positioned in the absorbent area <NUM> of the dressing. The absorbent layer <NUM> can retain wound fluid within thereby preventing fluid passage of wound exudates into the electronics area <NUM> of the dressing. The wound fluids can flow through the wound contact layer <NUM>, to the lower spacer layer <NUM>, and into the absorbent layer <NUM>. The wound fluids are then spread throughout the absorbent layer <NUM> and retained in the absorbent layer <NUM> as shown by the directional arrows for wound fluids in <FIG>.

The electronics area <NUM> of the dressing can include a plurality of layers of spacer material <NUM>. In some embodiments, the electronic components <NUM> can be embedded within the plurality of layers of spacer material <NUM>. The layers of spacer material can optionally have recesses or cut outs to embed the electronic components within whilst providing structure to prevent collapse. As described above, the electronic components <NUM> can optionally include a pump, a power source, a controller, and/or an electronics package, although any suitable electronic component is appreciated. A partition <NUM> can optionally be positioned between the absorbent area <NUM> and the electronics area <NUM>. The partition <NUM> can separate the absorbent layer <NUM> and lower air flow spacer layer <NUM> from the electronic housing segment of the dressing in the electronic area. The partition <NUM> can prevent wound fluid (e.g., wound exudate) from entering the electronic housing section of the dressing. In some embodiments, the partition can be a non-porous dam or other structure. The non-porous dam <NUM> can include a cyanoacrylate adhesive bead or a strip of silicone. The air pathway through the dressing is shown in <FIG> by directional arrows. The air flows through the wound contact layer <NUM>, the lower spacer layer <NUM>, and the absorbent layer <NUM> and into the first spacer layer <NUM>. The air can travel horizontally through the first spacer layer <NUM> over and around the partition <NUM> into the electronics area of the dressing.

As shown in <FIG>, the wound dressing system <NUM> can include a fluid ingress inhibition component <NUM> in fluid communication with a pump <NUM>. The component <NUM> can allow gas (e.g., air) but inhibit liquid (e.g., wound exudate) from passing through. In some embodiments, the wound dressing layers and the component <NUM> can be used with or without the optional partition <NUM>. The component <NUM> can provide a plurality of flow paths between an interior of the wound dressing <NUM> and the pump <NUM> so that occlusion (e.g., from wound exudate) of the pump <NUM> is inhibited. Advantageously, should any of the plurality of flow paths become occluded, one or more of the other flow paths of the plurality will be able to maintain an uninterrupted flow path between the wound dressing <NUM> and the pump <NUM>. Such flow path redundancy can advantageously make operation of wound dressing systems <NUM> more stable and reliable. In this way, the component <NUM> can allow a more stable target pressure to be delivered to a wound site by ensuring that there is an open flow path between the wound dressing <NUM> and the pump <NUM> and by inhibiting occlusions that would otherwise cause the target pressure to be more varied. In some embodiments, the surface area of the component <NUM> can advantageously increase the contact area between the pump <NUM> and the wound dressing <NUM>, thereby providing more flow paths into the inlet of the pump <NUM> for the same sized inlet. In some embodiments, the wound dressing system <NUM> can include two or more components <NUM>. For example, in some embodiments, the wound dressing system <NUM> can include between two and ten or more components <NUM>. The exact number used may depend on a number of factors, including the size of the wound site and the wound exudate discharge rate, in addition to the space constraints of the wound dressing, as well as other factors.

In some embodiments, the component <NUM> can be made of a hydrophobic material that repels wound exudate, thereby inhibiting the ingress of fluid into the component <NUM> and ultimately the pump <NUM>. In some embodiments, component <NUM> can be a hydrophobic coated material. In some embodiments, the component <NUM> can be made of a porous material. The pores can be small enough to inhibit the ingress of fluid through the component <NUM> due to capillary action (i.e., from surface tension of the wound exudate against the component <NUM>) and the pressure differential between the environment and the wound dressing, but large enough to permit the passage of air. For example, in some embodiments, the component <NUM> can be made of a material that has a pore size in the range of approximately <NUM> microns to approximately <NUM> microns. For example, in some embodiments, the material of the component <NUM> can have a pore size of approximately <NUM> microns. In some embodiments, the material of the component <NUM> can have a pore size of approximately <NUM> microns. However, it will be understood that any suitable pore size is appreciated. In some embodiments, the component can be a foam or a foam-like material. The hydrophobic nature of the material of the component <NUM> and/or its pore size can function to inhibit the flow of wound exudate from the wound dressing <NUM> to the pump <NUM>. The component <NUM> thereby inhibits the pump <NUM> in the wound dressing system <NUM> from discharging wound exudate from the wound dressing <NUM>.

As described above, the material of the component <NUM> can be porous. In some embodiments, the plurality of flow paths through the component <NUM> can be defined by a series of sequentially connected pores formed in the material of the component <NUM>, beginning with pore(s) in fluid communication with an interior of the wound dressing <NUM> and positioned on the exterior of the component <NUM> and ending with pore(s) in fluid communication with the pump <NUM> and positioned on the interior of the component <NUM>. Pores advantageously provide flow path redundancy because of their lattice arrangement and interconnected structure. The plurality of flow paths through the component <NUM> that connect the first pore(s) in fluid communication with an interior of the wound dressing <NUM> and the last pore(s) in fluid communication with the pump <NUM> can be straight and/or tortuous. A group of open pores can effectively create one or more larger flow channels through the component <NUM> that can sizably adjust as one or more occlusions materialize inside and/or outside the component <NUM>. In some embodiments, one or more pores can define one or more overlapping flow paths. For example, if one or more adjacent and/or neighboring pores of an open pore become occluded by wound exudate, the open pore can maintain an open path from the wound dressing <NUM> to the pump <NUM> by helping to redefine one or more flow paths around the one or more occluded pores. It will be appreciated that the plurality of flow paths through the component can be formed with any suitable structure. For example, in addition to or in lieu of pores, the plurality of flow paths can be formed by one or more channels extending through the component <NUM>.

In some embodiments, the component <NUM> can be a porous polymer component. The porous polymer component can be machined and/or molded (e.g., injection molded) into any suitable shape. For example, <FIG> illustrate three differently shaped porous polymer components <NUM> in fluid communication with a pump <NUM>. <FIG> illustrates a crescent-shaped component <NUM>. <FIG> illustrates a thimble-shaped component <NUM> with a cylindrical body and rounded terminal end. <FIG> illustrates two thimble-shaped components <NUM> with cylindrical bodies and flat terminal ends. Each of the components <NUM> can allow gas (e.g., air) to pass from various points in the wound dressing (not shown) into the pump <NUM> through one or more of a plurality of flow paths. The porous polymer component can be formed from POREX®, PORVAIR®, or any other suitable hydrophobic material, such as, for example, polyethylene and/or polypropylene, among others. In some embodiments, the porous polymer component can be formed from PORVAIR Vyon® porous polymer. As described above, the material of the component <NUM> can be made of a material that has a pore size in the range of approximately <NUM> microns to approximately <NUM> microns (e.g., <NUM> microns, <NUM> microns). For example, in some embodiments, the material of the component <NUM> can have a pore size of approximately <NUM> microns (e.g., <NUM> microns). In some embodiments, the material of the component <NUM> can have a pore size of approximately <NUM> microns (e.g., <NUM> microns). However, it will be understood that any suitable pore size is appreciated.

The components <NUM> shown in <FIG> are shown directly or indirectly coupled to an inlet 1304a of the pump <NUM>. For example, <FIG> illustrates a component <NUM> directly coupled to the pump inlet 1304a and <FIG> illustrate components <NUM> indirectly coupled to the pump inlet 1304a via an intermediate tubular member <NUM>. <FIG> also illustrates a Y-shaped splitter <NUM> that connects the two components <NUM> to the intermediate tubular member <NUM>. In some embodiments, the intermediate tubular member <NUM> and the Y-shaped splitter <NUM> in <FIG> can be a unitary piece. The internal diameter of the intermediate tubular member <NUM> and the Y-shaped splitter <NUM> can be in the range of approximately <NUM> to approximately <NUM>, such as for example, <NUM>. Of course, it will be understood that any suitable arrangement and structure is appreciated.

Although not shown in <FIG>, a non-return valve and/or an exhaust system can be coupled to the pump outlet 1304b. Additional disclosure relating to exhaust systems and non-return valves can be found in International Application No. <CIT>, titled "WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING. " Advantageously, the component <NUM> can inhibit wound exudate from being drawn from the wound site through the pump and into the non-return valve and/or exhaust system.

<FIG> illustrate cross-sectional views of the corresponding components <NUM> shown in <FIG>, respectively. For example, <FIG> illustrates the component <NUM> of <FIG> having a port <NUM> that receives a portion of the pump inlet 1304a. <FIG> similarly illustrate components <NUM> having ports <NUM>. In some embodiments, the component <NUM> can receive a portion of and/or be bonded to the member to which it connects (e.g., a pump inlet). For example, in some embodiments, the component <NUM> in <FIG> can be bonded (e.g., glued or heat welded) to the pump inlet 1304a. In some embodiments, the component <NUM> in <FIG> can freely slide over the pump inlet 1304a. One or more surrounding features of the wound dressing system <NUM> can help keep the component in place (e.g., compression between the cover layer <NUM> and the wound contact layer <NUM> shown in <FIG>).

<FIG> illustrate a fluid ingress inhibition system similar to the system of <FIG> sitting on top of a wound dressing padding or other wound dressing layer. <FIG> illustrates two components <NUM> sitting on top of a layer of the dressing with the cover layer <NUM> removed. <FIG> shows <FIG> with the cover layer <NUM> or other dressing layer drawn down onto the various internal components, including the two components <NUM>.

In some embodiments, the component <NUM> does not reduce the pump flow rate by more than <NUM>/min. For example, in some embodiments, the component <NUM> can reduce the pump flow rate in the range of <NUM>/min to <NUM>/min (e.g., from <NUM>/min to <NUM>/min). In some embodiments, the component <NUM> does not reduce the free performance of the pump by more than <NUM>%. For example, in some embodiments, the component <NUM> can reduce the free performance of the pump in the range of <NUM>% to <NUM>%.

In some embodiments, the component <NUM> can be a micro porous membrane attached to a pump inlet. In some embodiments, the membrane can be formed into the shape of a pouch to fit over and attach to the pump inlet. A 3d spacer (e.g., fabric) can be disposed in the pouch to inhibit the membrane from collapsing. In some embodiments, the pouch can be elongate in form, but it will be appreciated that the pouch can take on any suitable form. The membrane can be hydrophobic to repel fluid (e.g., wound exudate) and have a porosity that inhibits fluid ingress into the pump inlet due to capillary action. For example, in some embodiments, the micro porous membrane can be made of Versapore having a <NUM> pore size (Pall).

In some embodiments, the component <NUM> can be one or more lengths of fine bore tubing with a plurality of holes disposed along their lengths. The one or more lengths of fine bore tubing can form one or more loops between a pump inlet and a wound dressing. As another example, the one or more lengths of fine bore tubing can extend from the pump inlet to one or more different points in the wound dressing, similar to the way in which the two components <NUM> in <FIG> are positioned at two different points in the wound dressing. The size of the bore in the tubing can have an internal diameter such that the tubing resists collapse under reduce pressure.

In some embodiments, the component <NUM> is designed so that a significant pressure drop is avoided by its use. In this way, the component <NUM> prevents the pump <NUM> from having to work harder and consume more power from any added resistance it may add to the flow path from the wound dressing to the environment through the pump <NUM>.

<FIG> illustrate embodiments of an electronics unit <NUM> including a pump <NUM> and a component <NUM> directly coupled to the pump inlet 1704a. <FIG> illustrates the top view of the electronics unit. <FIG> illustrates a bottom or wound facing surface of the electronics unit. The electronics unit <NUM> can include a pump and other electronic component such as power source(s), sensor(s), connector(s), circuit board(s), user interface component(s) (such as button(s), switch(es), speaker(s), screen(s), etc.) and the like. In some embodiments, the electronics unit of <FIG> can be embedded into the electronics area <NUM> of the wound dressing as one unit.

In some embodiments, the component <NUM> can be pushed onto the pump inlet. This can be a friction fit. The port of the component <NUM> that receives a portion of the pump inlet can be sized and shaped to be a complementary fit around the pump inlet. In some embodiments, the component <NUM> can be bonded onto the pump inlet using a silicone sealant or any other sealant or sealing technique. In some embodiments, the electronics unit can be embedded within layers of the dressing in the electronics area <NUM>. In some embodiments, the layers of the dressing in the electronics area <NUM> can include cutouts or recesses into which the electronics unit <NUM> can be placed.

<FIG> illustrates the wound dressing layers for embedding or integrating an electronics unit. As illustrated in <FIG>, the dressing can include a wound contact layer <NUM> for placing in contact with the wound. Lower spacer layers <NUM> and <NUM>' are provided above the wound contact layer <NUM>. In some embodiments, the spacer layer <NUM> can be a separate layer from spacer layer <NUM>' as shown in <FIG>. In other embodiments, the lower spacer layers <NUM> and/or <NUM>' can be a continuous layer of spacer material that is below both the electronics area and the absorbent area. The lower spacer layers <NUM> and <NUM>' can assist in distributing pressure evenly to the wound surface and/or wicking fluid away from the wound. An absorbent layer <NUM> can be positioned above the lower spacer layer <NUM> and/or <NUM>'. A dressing layer <NUM> can include cutouts or recesses <NUM> for embedding the electronic components <NUM> within the layer <NUM>. In some embodiments, the layer <NUM> can be an absorbent material. In some embodiments, the dressing layer <NUM> and absorbent layer <NUM> can be one continuous piece of absorbent material. Alternatively, in some embodiments, the layer <NUM> can be a spacer layer or transmission material. In some embodiments, the cutouts or recesses <NUM> can be sized and shaped to embed a pump <NUM>, power source <NUM>, and/or other electronic components of the electronics unit. In some embodiments, the pump <NUM>, power source <NUM>, and/or other electronic components can be incorporated into the cutouts or recesses <NUM> as individual components or as an electronic assembly as shown in <FIG>. An upper layer <NUM> optionally can be provided above the absorbent layer <NUM>, layer <NUM>, and/or electronic components <NUM>. A cover layer or backing layer <NUM> can be positioned over the upper spacer layer. In some embodiments, when the upper layer <NUM> is not used, the cover layer or backing layer <NUM> can be provided above the absorbent layer <NUM>, layer <NUM>, and/or electronic components <NUM>. The backing layer <NUM> can form a seal to the wound contact layer <NUM> at a perimeter region enclosing the spacer layers <NUM>, <NUM>', and <NUM>, the absorbent layer <NUM>, layer <NUM>, and electronic components <NUM>. In some embodiments, the backing layer <NUM> can be a flexible sheet of material that forms and molds around the dressing components when they are applied to the wound. In other embodiments, the backing layer <NUM> can be a material that is preformed or premolded to fit around the dressing components as shown in <FIG>.

The component <NUM> is provided on the inlet of the pump <NUM>. In some embodiments, the hydrophobicity of the component <NUM> can keep the inlet to the pump free of exudate. In some embodiments, the component <NUM> can be in contact with and/or in fluid communication with superabsorbent and/or absorbent material. In this configuration, the component <NUM> can prevent liquid from being pulled through to the inlet of the pump when negative pressure is applied. The component <NUM> can be made of a material with a pore size larger than the pore size of traditional hydrophobic filters and liquid could get through if the material of the component were by itself in contact with water. However, the hydrophobicity of the hydrophobic component <NUM> with a pore size as described herein can be in contact with the superabsorber and/or absorbent material and can prevent exudate from being pulled through the inlet of the pump when negative pressure is applied.

<FIG> illustrates an embodiment of a component <NUM>, as claimed, with a port <NUM> for coupling to the pump inlet. The port <NUM>, similar to port <NUM> of <FIG>, is shaped to receive a portion of the pump inlet 1304a. In some embodiments, the shape of the pump inlet 1304a can be tubular or cylindrical as shown in the cross-section of the pump inlet 1304a in <FIG>. In some embodiments, the component <NUM> can receive a portion of and/or be bonded to the member to which it connects (e.g., a pump inlet). For example, in some embodiments, the component <NUM> can be bonded (e.g., glued or heat welded) to the pump inlet 1304a. In some embodiments, the component <NUM> can freely slide over the pump inlet 1304a. One or more surrounding features of the wound dressing system can help keep the component in place (e.g., compression between the cover layer and the wound contact layer).

Claim 1:
A wound dressing apparatus (<NUM>) comprising:
a wound dressing configured to be positioned over a wound site,
a negative pressure source (<NUM>, <NUM>) disposed on or positioned within the wound dressing,
the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and
a porous polymer component (<NUM>, <NUM>) fitted to the inlet of the negative pressure source and in fluid communication with the inlet,
the porous polymer component comprising a three-dimensional body defining a plurality of flow paths between an interior of the wound dressing and the inlet such that occlusion of the inlet is inhibited;
characterized in that
the negative pressure source is a pump and wherein the porous polymer component is provided on the inlet of the pump and
wherein the porous polymer component comprises a port (<NUM>, <NUM>) - that is shaped to receive a portion of the pump inlet.