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.

Embodiments of the present disclosure relate to apparatuses and methods 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. An electronics assembly can be incorporated into the absorbent material of the dressing to prevent pooling of wound exudate and maintain conformability of the dressing. 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.

According to the invention, a wound dressing apparatus can comprise a wound contact layer, the wound contact layer can comprise a proximal wound-facing face and a distal face, wherein the proximal wound-facing face is configured to be positioned in contact with a wound, a spacer layer comprising a proximal wound-facing face and a distal face, the spacer layer positioned over the distal face of the wound contact layer, an absorbent layer positioned on the distal face of the spacer layer, an electronics unit comprising a negative pressure source and/or electronic components, wherein the absorbent layer comprises a recess configured to receive the electronics unit and the absorbent layer is configured to be in fluid communication with the electronics unit and a cover layer configured to cover and form a seal over the wound contact layer, the spacer layer, the absorbent layer, and the electronics unit.

The wound dressing apparatus of the preceding paragraph or in other embodiments can include one or more of the following features. The electronic components can comprise one or more of a power source, a flexible circuit board, a sensor, a switch, and/or a light or LED indicator. The wound dressing further comprises a negative pressure source inlet protection mechanism and a negative pressure source outlet or exhaust. The negative pressure source outlet or exhaust can comprises an antibacterial membrane and/or a non-return valve. The cover layer can comprise an aperture over the outlet or exhaust. The negative pressure source inlet protection mechanism can comprise a hydrophobic material configured to prevent fluid from entering the negative pressure source.

Embodiments disclosed herein relate to apparatuses and methods (unclaimed) of treating a wound with reduced pressure, including a source of negative pressure and wound dressing components and apparatuses. The apparatuses and components comprising 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>. The disclosures of both of these patents are hereby incorporated by reference in their entirety.

International Application <CIT>, and published as <CIT>, is an application, 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 International Application No. <CIT>, titled "APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,"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".

Embodiments of the wound dressings, wound treatment apparatuses and methods described herein relating to wound dressings with electronics incorporated into the dressing may also be used in combination or in addition to those described in International Application <CIT>, titled "WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING".

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. The wound dressing can include various material layers described here and described in further detail in International Application No. <CIT>, entitled WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING. The material layers can include a wound contact layer, one or more absorbent layers, one or more spacer or transmission layers, and a backing layer or cover layer covering the one or more absorbent and spacer or transmission layers. The wound dressing can be placed over a wound and sealed to the wound with the pump and/or other electronic components contained under the cover layer within the wound dressing. In some embodiments, the dressing can be provided as a single article with all wound dressing elements (including the pump) pre-attached and integrated into a single unit. In some embodiments, a periphery of the wound contact layer can be attached to the periphery of the cover layer enclosing all wound dressing elements as illustrated in <FIG>.

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 article to be applied to a patient. In some embodiments, 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> and an absorbent area <NUM>. The dressing can comprise a wound contact layer <NUM> (not shown in <FIG>) and a moisture vapor permeable film or cover layer <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> as shown in <FIG>.

The dressing can comprise a wound contact layer <NUM>, a transmission layer <NUM>, an absorbent layer <NUM>, a moisture vapor permeable film or cover layer <NUM>, <NUM> positioned above the wound contact layer, transmission 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> 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> 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> 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 or transmission 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 transmission 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 transmission 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> helps lock the liquid away or itself wicks the liquid onwards towards the cover layer <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> 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 cover layer <NUM>.

The material of the absorbent layer <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> 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> may typically be manufactured from ALLEVYN™ foam, Freudenberg <NUM>-<NUM>-<NUM> or Chem-Posite™11C-<NUM>. In some embodiments, the absorbent layer <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.

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 cover layer <NUM> is preferably gas impermeable, but moisture vapor permeable, and can extend across the width of the wound dressing <NUM>. The cover layer <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 cover layer <NUM> and a wound site where a negative pressure can be established. The cover layer <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 cover layer <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 cover layer <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 cover layer increases when the cover layer becomes wet. The moisture vapor permeability of the wet cover layer may be up to about ten times more than the moisture vapor permeability of the dry cover 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, the electronics unit can be within absorbent material in the electronics area <NUM> of the dressing as described herein. As illustrated in <FIG>, the electronics unit <NUM> can be positioned within an absorbent material <NUM> but off to the side of the absorbent area.

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 transmission layers and/or one or more absorbent layer positioned above the wound contact layer <NUM> and below the cover layer <NUM> of the dressing.

In some embodiments, the electronics area <NUM> of the dressing can comprise electronic components <NUM>. In some embodiments, the electronics area <NUM> of the dressing can comprise a plurality of layers of transmission material and/or absorbent material and electronic components <NUM> can be embedded within the plurality of layers of transmission material and/or absorbent material. The layers of transmission or absorbent material can have recesses or cut outs to embed the electronic components <NUM> within whilst providing structure to prevent collapse. The electronic components <NUM> can include a pump, power source, controller, and/or an electronics package.

A pump exhaust can be provided to exhaust air from the pump to the outside of the dressing. The pump exhaust can be in communication with the electronics area <NUM> and the outside of the dressing.

As used herein the upper layer, top layer, or layer above refers to a layer furthest from the surface of the skin or wound while the dressing is in use and positioned over the wound. Accordingly, the lower surface, lower layer, bottom layer, or layer below refers to the layer that is closest to the surface of the skin or wound while the dressing is in use and positioned over the wound. Additionally, the layers can have a proximal wound-facing face referring to a side or face of the layer closest to the skin or wound and a distal face referring to a side or face of the layer furthest from the skin or wound.

<FIG> illustrates a wound dressing apparatus incorporating the pump and/or other electronic components within the wound dressing and offset from the absorbent layer. In some embodiments, as shown in <FIG>, the absorbent area <NUM> comprises a transmission layer <NUM> positioned above the wound contact layer <NUM>. An absorbent layer <NUM> can be provided above the transmission layer <NUM>. In some embodiments, the electronics area <NUM> can include an electronics unit (shown in <FIG>). In some embodiments, the electronics unit is provided directly over the wound contact layer. In other embodiments, the electronics unit can be placed above a layer of wicking material, absorbent material, or transmission material that sits above the wound contact layer <NUM> of the dressing. For example, as shown in <FIG>, the electronics unit <NUM> may be positioned over the transmission layer <NUM>. In some embodiments, the transmission layer <NUM> can be a single layer of material extending below the electronics unit <NUM> and the absorbent material <NUM>. Thus, in some embodiments, the transmission layer <NUM> extends continuously through the absorbent area <NUM> and the electronics area <NUM>. In alternative embodiments, the transmission layer below the electronics unit can be a different transmission layer than the transmission layer below the absorbent material <NUM>. The transmission layer <NUM>, absorbent material <NUM>, and electronics unit <NUM> can be covered with a cover layer <NUM> that seals to a perimeter of the wound contact layer <NUM> as shown in <FIG>.

The electronics area <NUM> can include an electronics unit <NUM> positioned below the cover layer <NUM> of the dressing. The electronics unit is surrounded by a material to enclose or encapsulate a negative pressure source and electronics components by surrounding the electronics. In some embodiments, this material can be a casing. In some embodiments, the electronics unit can be encapsulated or surrounded by a protective coating, for example, a hydrophobic coating as described herein. The electronics unit can be in contact with the dressing layers in the absorbent area <NUM> and covered by the cover layer <NUM>. As used herein, the electronics unit includes a lower or wound facing surface that is closest to the wound and an opposite, upper surface, furthest from the wound when the wound dressing is placed over a wound.

<FIG> illustrate an embodiment of the electronics unit <NUM>. <FIG> illustrates an embodiment of a pump and electronics unit <NUM> that can be incorporated into a wound dressing. The electronics unit <NUM> of <FIG> is shown without an electronics casing or other dressing material. <FIG> illustrate embodiments of the pump and electronics unit <NUM>. <FIG> illustrates the top view of the electronics unit. <FIG> illustrates a bottom or wound facing surface of the electronics unit.

As illustrated in <FIG>, the electronics unit <NUM> can include single button <NUM> on the upper surface of the unit. The single button <NUM> can be used as an on/off button or switch to stop and start operation of the pump and/or electronic components. The switch <NUM> can be a dome type switch configured to sit on the top of the pump. Because the switch is situated within the dressing the cover layer can be easily sealed around or over the switch. In some embodiments, the cover layer can have an opening or hole positioned above the switch. The cover layer can be sealed to the outer perimeter of the switch <NUM> to maintain negative pressure under the wound cover. The switch can be placed on any surface of the electronics unit and can be in electrical connection with the pump.

The electronics unit <NUM> includes one or more vents or exhausts <NUM> for the pump outlet. However, the vent or exhaust <NUM> is positioned at the outlet of the pump and extending to the upper surface of the electronics unit. As shown in <FIG>, the pump outlet exhaust <NUM> is attached to the outlet of the pump and provides communication with the top surface of the dressing. In some embodiments, the exhaust <NUM> can be attached to the outlet end of the pump and can extend out from the pump at a <NUM>-degree angle from the pump orientation to communicate with the top surface of the dressing. The exhaust <NUM> can include an antibacterial membrane and a non-return valve. The exhausted air from the pump can pass through the pump outlet and exhaust mechanism <NUM>. In some embodiments, the cover layer <NUM> can include apertures or holes positioned above the exhaust vents <NUM> and/or membrane. The cover layer <NUM> can be sealed to the outer perimeter of the exhaust vents <NUM> to maintain negative pressure under the wound cover <NUM>. In some embodiments, the exhausted air can be exhausted through the gas permeable material or moisture vapor permeable material of the cover layer. In some embodiments, the cover layer does not need to contain apertures or holes over the exhaust and the exhausted air is expelled through the cover layer. In some embodiments, the pump outlet mechanism <NUM> can be a custom part formed to fit around the pump as shown in <FIG>. The electronic unit <NUM> can include a pump inlet protection mechanism <NUM> (shown in <FIG>) positioned on the portion of the electronic unit closest to the absorbent area and aligned with the inlet of the pump <NUM>. The pump inlet protection mechanism is positioned between the pump inlet and the absorbent area or absorbent layer of the dressing. The pump inlet protection mechanism can be formed of a hydrophobic material to prevent fluid from entering the pump.

In some embodiments, the upper surface of the electronics unit can include one or more indicators <NUM> for indicating a condition of the pump and/or level of pressure within the dressing. The indicators can be small LED lights or other light source that are visible through the dressing material or through holes in the dressing material above the indicators. The indicators can be green, yellow, red, orange, or any other color. For example, there can be two lights, one green light and one orange light. The green light can indicate the device is working properly and the orange light can indicate that there is some issue with the pump (e.g. dressing leak, saturation level of the dressing, and/or low battery).

<FIG> illustrates an embodiment of a pump and electronics unit <NUM>. The electronics unit <NUM> includes a pump <NUM> and can include one or more batteries <NUM> or other power source to power the pump <NUM> and other electronics. The pump can operate at about <NUM> volts or about <NUM> volts. The two batteries can allow for a more efficient voltage increase (<NUM> volts to <NUM> volts) than would be possible with a single battery.

The batteries <NUM> can be in electrical communication with a flexible circuit board <NUM>. In some embodiments, one or more battery connections are connected to a surface of the flexible circuit board <NUM>. In some embodiments, the flexible circuit board can have other electronics incorporated within. For example, the flexible circuit board may have various sensors including, but not limited to, one or more pressure sensors, temperature sensors, optic sensors and/or cameras, and/or saturation indicators.

In such embodiments, the components of the electronics unit <NUM> may include a protective coating to protect the electronics from the fluid within the dressing. The coating can provide a means of fluid separation between the electronics unit <NUM> and the absorbent materials of the dressing. The coating can be a hydrophobic coating including, but not limited to, a silicone coating or polyurethane coating. The pump inlet component can be used to protect the pump from fluid on the inlet and the pump outlet mechanism can include a non-return valve that protects fluid from entering the outlet as described in more detail with reference to PCT International Application No. <CIT>, titled WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO WOUND DRESSING and PCT International Application No. <CIT>, titled WOUND DRESSINGS AND METHODS OF USE WITH INTEGRATED NEGATIVE PRESSURE SOURCE HAVING A FLUID INGRESS INHIBITION COMPONENT.

The electronics unit <NUM> includes one or more slits, grooves or recesses <NUM> in the unit between the pump and the two batteries. The slits, grooves or recesses <NUM> can allow for the electronics unit <NUM> to be flexible and conform to the shape of the wound. The unit <NUM> can have two parallel slits, grooves or recesses <NUM> forming three segments of the electronics unit <NUM>. The slits, grooves or recesses <NUM> of the unit <NUM> create hinge points or gaps that allows for flexibility of the electronics unit at that hinge point. The pump exhaust vents <NUM>, switch <NUM>, and indicator <NUM> are shown on the top surface surrounded by the electronics unit <NUM>. As illustrated, one embodiment of the electronics unit <NUM> has two hinge points to separate the unit into three regions or panels, for example one to contain one battery, one to contain the pump, and one to contain another battery. In some embodiments, the slits, grooves or recesses may extend parallel with a longitudinal axis of the dressing that extends along the length of the dressing through the electronics area of the dressing through the absorbent area of the dressing.

<FIG> illustrates an embodiment of a wound dressing incorporating an electronics unit <NUM> within the dressing. The wound dressing includes a wound contact layer <NUM>. The dressing can also include a transmission layer <NUM> which may be made of a 3D material above the wound contact layer. In some embodiments, the electronics sub assembly or electronics unit <NUM> can be embedded in an aperture or hole in an absorbent pad <NUM> towards one end of the dressing, as depicted in <FIG>. As shown in the cross sectional view of the wound dressing layers in <FIG>, the absorbent material <NUM> can be positioned on both sides of the electronic components <NUM>.

In some embodiments, the absorbent components and electronics components can be overlapping but offset. For example, a portion of the electronics area can overlap the absorbent area, for example overlapping the superabsorber layer, but the electronics area is not completely over the absorbent area. Therefore, a portion of the electronics area can be offset from the absorbent area. The dressing layer and electronic components can be enclosed in a wound contact layer <NUM> positioned below the lower most layer and a cover layer (not shown) positioned above the absorbent layer and electronics. The wound contact layer and cover layer can be sealed at a perimeter enclosing the dressing components. In some embodiments, the cover layer can be in direct physical contact with the absorbent material, and/or the electronics unit. In some embodiments, the cover layer can be sealed to a portion of the electronics unit and/or casing, for example, in areas where holes or apertures are used to accommodate the electronic components (e.g. a switch and/or exhaust).

<FIG> illustrate an embodiment of a wound dressing incorporating an electronics unit resting in the absorbent layer. <FIG> illustrates a transmission layer <NUM>. <FIG> illustrates an absorbent layer <NUM> provided over the entire length of the transmission layer <NUM>. The absorbent layer has one recess, cutout, or slot <NUM> in the portion of the absorbent layer <NUM> located in the electronics area. In <FIG>, the transmission layer <NUM> is visible in the recess <NUM> of the absorbent layer <NUM>. The recess <NUM> is spaced and sized to fit the outer perimeter of the batteries and pump assembly of the electronics unit <NUM> in one recess. In some embodiments, the recess in the absorbent layer can include multiple recesses that are sized to fit individual components of the electronics unit <NUM>, for example, the batteries and pump assembly as illustrated in embodiments described with reference to <FIG>, <FIG>, and <FIG>. <FIG> illustrates the electronics unit <NUM> positioned within the recess <NUM> of the absorbent layer <NUM>. The dressing layers and components shown in <FIG> can be enclosed in a wound contact layer (not shown) positioned below the transmission layer and a cover layer (not shown) positioned above the absorbent layer and electronics. The wound contact layer and cover layer can be sealed at a perimeter enclosing the dressing components.

The wound dressing of <FIG> include an overlay layer <NUM> comprising an additional layer of material positioned above the dressing layers. In some embodiments, the additional layer can include a masking or obscuring layer positioned above the dressing layers. The overlay layer <NUM> can be positioned above the absorbent layer and electronics and below the cover layer <NUM>. In some embodiments, the overlay layer <NUM> can include an aperture <NUM> over a portion of the electronic components to allow the electronic components to be accessible from above the overlay layer. In some embodiments, the overlay layer <NUM> can be an opaque material that does not allow the wound exudate or other fluid to be visible from a top view of the wound dressing. In some embodiments, the overlay layer can be an absorbent or transmission layer as described herein. In some embodiments, the overlay layer can comprise a conformable material overlaying and overbordering the perimeter of the lower layers of transmission and absorbent materials so as to protect the cover layer from being punctured by the lower layers when sealed over the dressing layers as described in more details below.

The wound dressing can include an electronics label or covering <NUM> positioned over the aperture <NUM> in the overlay layer <NUM>. In some embodiments, the label or covering <NUM> can be positioned under the cover layer <NUM>. In other embodiments, the cover layer <NUM> can be positioned below the label and can also have an aperture to allow the label or covering <NUM> to communicate with the underlying electronic components.

<FIG> illustrate the wound dressing of <FIG> absorbing and retaining fluids while negative pressure is applied to the dressing.

<FIG> illustrate a label or covering <NUM> that can be positioned over and cover the electronics and an opening <NUM> in the overlay layer <NUM>.

<FIG> illustrates an embodiment of wound dressing layers incorporating the electronic components within the wound dressing. <FIG> illustrates a wound dressing with a wound contact layer <NUM> configured to contact the wound. A transmission layer or spacer layer <NUM> is provided over the wound contact layer <NUM>. The transmission layer <NUM> can assist in transmitting and distributing negative pressure over the wound site.

A first layer of apertured absorbent material <NUM> can be provided over the transmission layer <NUM>. The first apertured absorbent layer <NUM> can include an aperture <NUM>. In some embodiments, the aperture <NUM> can be sized and shaped to fit the electronics unit <NUM> therein. The first apertured absorbent layer <NUM> can be sized and shaped to the size of the electronics area and does not extend into the absorbent area. In some embodiments, the apertures <NUM> can be shaped and sized to fit the individual components of the electronics unit <NUM>.

A second apertured absorbent layer <NUM> can be provided over the first absorbent layer <NUM>. In some embodiments, the second absorbent layer <NUM> include apertures <NUM>. The second absorbent layer <NUM> can be sized and shaped to the size of the electronics area and absorbent area. In some embodiments, the apertures <NUM> can be shaped and sized to fit the individual components of the electronics unit <NUM>.

An electronics unit <NUM> can be positioned in the apertures <NUM> and <NUM> of the first and second apertured absorbent material <NUM> and <NUM>. The electronics unit <NUM> can include a pump <NUM>, power source <NUM>, and a printed circuit board <NUM>. In some embodiments, the pump <NUM> can include a pump inlet mechanism <NUM> and an outlet mechanism <NUM>. In some embodiments, the printed circuit board <NUM> can include electronics including but not limited to a switch, sensors, and LEDs as described herein. In some embodiments, the circuit board <NUM> can include one or more hole to be positioned over one or more exhaust vents (not shown) in the outlet mechanism <NUM> as described in more detail herein.

An overlay layer <NUM> can be provided over the electronics components <NUM> and absorbent layer <NUM>. In some embodiments, the overlay layer <NUM> can be one or more layers of absorbent and/or transmission material as described herein. In some embodiments, the overlay layer <NUM> can comprise a conformable material overlaying and overbordering the perimeter of the lower layers of transmission and absorbent materials. In some embodiments, the overlay layer <NUM> can soften the edges of the wound dressing layers by decreasing the profile around the edges of the dressing layers. In some embodiments, the overlay layer <NUM> can be provided to protect the cover layer from being punctured by the lower layers when positioned over the dressing layers as described in more details below. The overlay layer <NUM> can include an aperture <NUM> to allow access to at least a portion of the electronics unit <NUM> positioned below.

A cover layer or backing layer <NUM> can be positioned over the overlay layer <NUM>. In some embodiments, when the overlay layer <NUM> is not used, the cover layer or backing layer <NUM> can be provided above absorbent layers <NUM>, and/or electronic components <NUM>. The cover layer <NUM> can form a seal to the wound contact layer <NUM> at a perimeter region enclosing the overlay layer <NUM>, absorbent layers <NUM> and <NUM>, electronic components <NUM>, and the transmission layer <NUM>. In some embodiments, the cover 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 cover layer <NUM> can be a material that is preformed or premolded to fit around the dressing components as shown in <FIG>. As used herein, the terms cover layer and backing layer can be used interchangeably to refer to the layer of material in the dressing configured to cover the layers of the wound dressing.

In some embodiments, the cover layer or backing layer <NUM> can include an aperture <NUM>. The aperture <NUM> can be positioned over at least a portion of the aperture <NUM> in the overlay layer <NUM> to allow access to at least a portion of the electronics unit <NUM> positioned below. In some embodiments, the apertures <NUM> and <NUM> can allow access to the switch and/or venting holes of the pump exhaust.

A label <NUM> can be provided over the apertures <NUM> and <NUM> and positioned over the exposed portion of the electronic components <NUM>. The label can include the vent holes <NUM>, indicator portions <NUM>, and/or switch cover <NUM>. The indicator portions <NUM> can include holes or transparent regions <NUM> for positioning over the one or more indicators or LEDs on the printed circuit board <NUM> below the label <NUM>. The holes or transparent regions <NUM> can allow for the indicators or LEDs to be visible through the label <NUM>. In some embodiments, the switch cover <NUM> can include a dome shaped cover positioned over the switch on the printed circuit board <NUM>. In some embodiments, the label <NUM> can include embossed features for the switch cover <NUM>. In some embodiments, the embossed features of the switch cover <NUM> can prevent accidental activation or deactivation of the device. In some embodiments, the switch or switch cover <NUM> can include a tab on the switch to prevent accidental activation or deactivation. The vent holes <NUM> of the label can allow exhaust from the pump outlet mechanism to pass through the label and exit the wound dressing to be exhausted to the atmosphere.

In some embodiments, the label can be positioned on top of the cover layer or backing layer <NUM>. The label can be sealed to the top surface of the cover layer. In other embodiments, the label <NUM> can be positioned above the overlay layer <NUM> and below the cover layer or backing layer <NUM>. In such embodiments, the cover layer <NUM> can have one or more apertures over one or more components of the label <NUM>. For example, the cover layer <NUM> can have apertures over the vent holes <NUM>, indicator portions <NUM>, and/or switch cover <NUM>.

<FIG> illustrates the individual layers of a wound dressing. <FIG> illustrates a first apertured absorbent material <NUM> cut to fit the size and shape of the electronics area.

<FIG> illustrates a second apertured absorbent layer <NUM> and a transmission layer <NUM>. Both the second absorbent layer <NUM> and transmission layer <NUM> can be a similar size and shape as shown in <FIG>. The first apertured absorbent material <NUM> can be a smaller apertured absorbent material than the size of the second apertured absorbent layer <NUM>.

<FIG> illustrates a transmission layer <NUM>, a first apertured absorbent layer <NUM>, a second apertured absorbent layer <NUM>, and overlay layer <NUM>. As shown in <FIG>, the overlay layer <NUM> can have a larger perimeter size than the other layers of the dressing as to overhang the edges of the other layers of the wound dressing. In some embodiments, the overlay layer <NUM> can have a smaller thickness than the absorbent layer <NUM> and transmission layer <NUM>. In other embodiments, the overlay layer <NUM> can have the same thickness or a greater thickness than the absorbent layer <NUM> and transmission layer <NUM>.

<FIG> illustrates the layers of the wound dressing incorporating an electronics assembly within the dressing. As shown in <FIG>, a transmission layer <NUM> can be placed over a wound contact layer <NUM>. <FIG> illustrates a bottom view of components of the wound dressing. <FIG> illustrates the bottom view of an electronic unit <NUM> embedded within the apertures of the first apertured absorbent layer <NUM> and the second apertured absorbent layer <NUM>. <FIG> illustrates a top view of an electronics unit <NUM> embedded within the apertures of the first apertured absorbent layer <NUM> (not shown) and the second apertured absorbent layer <NUM> placed over the transmission layer (not shown) and the wound contact layer <NUM>.

<FIG> illustrates the layers of the wound dressing device with the electronics unit <NUM> embedded within the first apertured absorbent layer <NUM> and the second apertured absorbent layer <NUM>. The first apertured absorbent layer <NUM> and the second apertured absorbent layer <NUM> can be placed over the transmission layer <NUM> and the wound contact layer <NUM>.

<FIG> illustrates an overlay layer <NUM> positioned over the dressing layers. The overlay layer <NUM> includes an opening or aperture <NUM> positioned over a portion of the electronics unit <NUM>. The aperture <NUM> can allow for access to the switch, pump outlet components, and visual indicators on the top surface of the electronics unit <NUM>.

A label or covering <NUM> can be positioned over and cover the electronics and an opening <NUM> in the overlay layer <NUM> as shown in <FIG> shows a cover layer <NUM> covering the overlay layer <NUM> and electronics covering <NUM> and underlying dressing and electronics components. The cover layer <NUM> can seal to the wound contact layer <NUM> (shown in <FIG>) at a perimeter region of the wound contact layer <NUM>. In some embodiments, the label or electronics covering <NUM> can be positioned over the cover layer <NUM>. In some embodiments, the cover layer <NUM> can seal over the electronics covering <NUM>. In some embodiments, the electronics covering <NUM> can include a switch cover <NUM>, one or more visual indicators <NUM>, and/or pump outlet vent(s) <NUM> as shown in <FIG>. In some embodiments, the cover layer <NUM> can include one or more holes in the cover layer <NUM> positioned over the switch and/or pump outlet vent(s). In some embodiments, the cover layer <NUM> can include a single hole that is positioned over the switch cover <NUM>, visual indicators <NUM>, and/or pump outlet vent(s) <NUM> in the covering or label <NUM> as shown in <FIG>. In some embodiments, the label can include embossed features for the switch cover <NUM>. In some embodiments, the embossed features of the switch cover <NUM> can prevent accidental activation or deactivation of the device. In some embodiments, the switch or switch cover <NUM> can include a tab on the switch to prevent accidental activation or deactivation.

The visual indicators <NUM> can provide an indication of operation of the negative pressure source and/or an indication of the level of negative pressure that is applied to the wound. In some embodiments, the visual indicators can include one or more light sources or LEDs. In some embodiments, the visual indicator light sources an illuminate to indicate a condition or change of condition. In some embodiments, the light source can illuminate in a particular sequence and/or color that indicates a condition. For example, in some embodiments, the light source can flash to notify the user that the device is operating properly. In some embodiments, the light source can automatically flash periodically and/or the light source can be activated by the switch or other button to light up and indicate a condition.

In some embodiments, the switch can be pressed and/or held down to power the dressing and electronics on and off. In some embodiments, once the switch is activated and the pump and associated colored LED, for example, green colored LED, can be used to conformed the dressing and integrated negative pressure source is operational. In some embodiments, during operation of the pump and dressing, the pump and dressing can enter the fault state indicated by a colored LED, for example, orange colored LED.

The electronics components are incorporated in the dressing. For example, the dressing components can be assembled to form one integrated negative pressure dressing to be positioned over a wound. The following assembly description describes an embodiment of the assembly of an integrated wound dressing. In some embodiments, some or all of the assembly process can be automated and/or any or all of the processes or procedures can be done in any order.

A transmission layer can be positioned over the wound contact layer as shown in <FIG>. In some embodiments, the transmission layer can be positioned with the larger pores facing upward or away from the wound. <FIG> illustrates a bottom view of some of the components of the wound dressing to illustrate the electronic components embedded within or fit into the apertures of the large apertured pad or absorbent layer and small apertured pad or absorbent layer. In <FIG>, the electronics assembly is positioned switch side down. <FIG> illustrates the top view of the electronics assembly within the apertured pads or absorbent material placed directly on top of the transmission layer as shown in <FIG> and <FIG>. The switch can be positioned on the top surface of the printed circuit board as shown in <FIG> and <FIG>.

The overlay layer <NUM> can be positioned over the apertured pads or absorbent material with the aperture in the overlay layer positioned over the switch of the electronics assembly. In some embodiments, the edges and/or the outer perimeter of the overlay layer <NUM> can be adhered or secured to the top or upper surface of the wound contact layer <NUM>. A top film or cover layer can be placed over the overlay layer <NUM> as shown in <FIG>. In some embodiments, the perimeter of the cover layer can be secured to the top or upper surface of the wound contact layer <NUM>. In some embodiments, if the cover layer is positioned over the printed circuit board, holes can be punctured in the top film at the location of the two exhaust ports. In other embodiments, the cover layer can be provided with one or more apertures that are placed over the two exhaust ports and/or other components of the electronics unit.

A label cover can be applied over the switch and/or other components of the electronics assembly that are exposed through the apertures of the overlay layer <NUM> and the cover layer. The indicator portions can include transparent portions or LED windows aligned with the LED's on the PCB when the label cover is applied. In some embodiments, the LED windows can include apertures in the label cover. In other embodiments, the LED windows can be transparent portions of the label cover. The exhaust holes can also be aligned with apertures in the label cover.

<FIG> illustrates a cross sectional layout of the material layers of the wound dressing incorporating an electronics assembly within the dressing. The dressing <NUM> included multiple material layers and an electronics assembly <NUM>. The wound dressing <NUM> includes an electronics area <NUM> including the electronics and an absorbent area or dressing area <NUM> that is intended to be applied to the wound as described with reference to <FIG>. As described herein, the one or more of the material layers can extend into both the electronics area <NUM> and the dressing area <NUM>. The dressing <NUM> can include a wound contact layer <NUM>, transmission layer <NUM>, absorbent layers <NUM> and <NUM>, an overlay layer, and a cover or backing layer <NUM> as illustrated in <FIG>. The absorbent layers <NUM> and <NUM> can include recesses or cutouts to receive the components of the electronics assembly <NUM> as described herein. In some embodiments, the overlay layer <NUM> and/or the cover layer <NUM> can include a cut out over the switch and/or indicators of the electronics assembly <NUM>. A label or covering <NUM> can be positioned to cover at least a portion of the electronics assembly <NUM> and any cutouts in the overlay layer <NUM> and/or the cover layer <NUM>. The label or covering <NUM> can be similar to the label or covering <NUM> as described previously with reference to <FIG> and <FIG>.

Before use, the dressing can include a delivery layer <NUM> adhered to the bottom surface of the wound contact layer. The delivery layer <NUM> can cover adhesive or apertures on the bottom surface of the wound contact layer <NUM>. In some embodiments, the delivery layer <NUM> can provided support for the dressing and can assist in sterile and appropriate placement of the dressing over the wound and skin of the patient. The delivery layer <NUM> can include handles <NUM> that can be used by the user to separate the delivery layer <NUM> from the wound contact layer <NUM> before applying the dressing <NUM> to a wound and skin of a patient.

The wound dressing with embedded electronics can be any shape or size to accommodate various types of wounds. For example, the wound dressing with embedded electronics can have a rectangular, rounded rectangular, square, T shaped, or any other shape or design. In some embodiments, the wound dressings with embedded electronics described herein can be rectangular or rounded rectangular shaped as illustrated with reference to <FIG>. In other embodiments, the wound dressings with embedded electronics described herein can be a T shaped as illustrated with reference to <FIG>.

Claim 1:
A wound dressing apparatus (<NUM>) comprising:
a wound contact layer (<NUM>) comprising a proximal wound-facing face and a distal face, wherein the proximal wound-facing face is configured to be positioned in contact with a wound;
a spacer layer (<NUM>) comprising a proximal wound-facing face and a distal face, the spacer layer positioned over the distal face of the wound contact layer;
an absorbent layer (<NUM>) positioned on the distal face of the spacer layer; an electronics unit (<NUM>) comprising a negative pressure source and electronic components wherein the electronics unit is surrounded by a material to encapsulate the negative pressure source and the electronics components;
wherein the absorbent layer comprises a recess configured to receive the electronics unit and the absorbent layer is configured to be in fluid communication with the electronics unit;
a cover layer (<NUM>) sealed to the wound contact layer at a perimeter to thereby enclose the wound dressing; the negative pressure source is characterised in that it comprises an inlet protection mechanism and an outlet or exhaust.