Patent Description:
Many different types of wound dressings are known for aiding in the healing process of a human or animal. 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. Topical negative pressure (TNP) therapy, sometimes referred to as vacuum assisted closure, negative pressure wound therapy (NPWT), or reduced pressure wound therapy, is widely recognized as a beneficial mechanism for improving the healing rate of a wound. Such therapy is applicable to a broad range of wounds such as incisional wounds, open wounds and abdominal wounds or the like.

TNP therapy assists in the closure and healing of wounds by reducing tissue oedema, encouraging blood flow, stimulating the formation of granulation tissue, removing excess exudates and may reduce bacterial load and, thus, infection to the wound. Furthermore, TNP therapy permits less outside disturbance of the wound and promotes more rapid healing.

In some instances, different types of TNP therapy systems may need to be used at different stages of the treatment. For example, a wound may initially contain and generate larger amounts of exudate, and the treatment may start with a system including a larger pump and a canister for the collection of greater volumes of wound exudate. As the healing progresses and less exudate is produced, the patient may be switched to a smaller disposable/portable device.

<CIT> relates to a system for negative pressure wound therapy.

According to the invention, there is provided a system for negative pressure wound therapy, the system comprising:
a drape comprising:.

The system of the preceding paragraph or in other embodiments can include one or more the following features. In some embodiments, the wound contact layer carries an adhesive portion on a lower surface thereof, the adhesive portion for forming a substantially fluid tight seal over a wound site. The wound contact layer may be perforated. In some embodiments, the cover layer is moisture vapor permeable. In some embodiments, the support layer comprises polypropylene, polyethylene terephthalate, or polyvinyl chloride. The support layer may be positioned above the spacer layer. The support layer may have greater stiffness than the cover layer. The support layer may comprise one or more perforations formed through a thickness of the support layer. The support layer may be positioned immediately below the cover layer, such that a portion of the support layer under the opening is exposed. In some embodiments, the system may further comprise a suction adapter having an applicator at a distal end of the suction adapter, wherein at least a portion of the applicator is configured to be attached to the exposed portion of the support layer when the suction adapter is coupled to the drape and form a fluid tight seal. In some embodiments, a proximal end of the suction adapter is configured to be fluidically connected to a source of negative pressure. In some embodiments, the drape further comprises a reinforcement member positioned above the cover layer. The reinforcement member may be attached to an upper surface of the cover layer using an adhesive. The reinforcement member may comprise a window formed through the reinforcement layer, wherein the window is configured to expose the opening of the cover layer when the reinforcement member is attached to the cover layer. The reinforcement member may comprise a material stiffer than the cover layer. In some embodiments, the system may further comprise a wound dressing, wherein at least a portion of the wound dressing is configured to be attached to the reinforcement member and coupled to the drape. An outer perimeter of the wound dressing may substantially conform to an outer perimeter of the reinforcement layer. In some embodiments, the cover layer is sealed to the wound contact layer in a border region around the circumference of the drape. In some embodiments, the support layer may be smaller than the spacer layer.

Embodiments disclosed herein relate to apparatuses, systems, devices of treating a wound with reduced pressure. 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.

Embodiments of the present disclosure are generally applicable to use in topical negative pressure (TNP) or reduced pressure 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, or removing excess exudate and can 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 can also assist in the healing of surgically closed wounds by removing fluid. In some embodiments, TNP therapy helps 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.

<FIG> illustrates an embodiment of a negative or reduced pressure wound treatment (or TNP) system <NUM> including a wound filler <NUM> placed inside a wound cavity <NUM>, the wound cavity sealed by a wound cover <NUM>. The wound filler <NUM> in combination with the wound cover <NUM> can be referred to as wound dressing. A flow path <NUM>, such as a single or multi lumen tube or conduit, is connected to the wound cover <NUM> with a negative pressure wound therapy device, for example pump assembly <NUM>, configured to supply reduced pressure. The wound cover <NUM> can be in fluidic communication with the wound cavity <NUM>. In any of the system embodiments disclosed herein, as in the embodiment illustrated in <FIG>, the pump assembly can be a canisterless pump assembly (meaning that exudate is collected in the wound dressing or is transferred via tube <NUM> for collection to another location). However, any of the pump assembly embodiments disclosed herein can be configured to include or support a canister. Additionally, in any of the system embodiments disclosed herein, any of the pump assembly embodiments can be mounted to or supported by the dressing, or adjacent to the dressing. The wound filler <NUM> can be any suitable type, such as hydrophilic or hydrophobic foam, gauze, inflatable bag, and so on. The wound filler <NUM> can be conformable to the wound cavity <NUM> such that it substantially fills the cavity. The wound cover <NUM> can provide a substantially fluid impermeable seal over the wound cavity <NUM>. The wound cover <NUM> can have a top side and a bottom side, and the bottom side adhesively (or in any other suitable manner) seals with wound cavity <NUM>. The conduit <NUM> or lumen or any other conduit or lumen disclosed herein can be formed from polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable material.

Some embodiments of the wound cover <NUM> can have a port (not shown) configured to receive an end of the conduit <NUM>. In other embodiments, the conduit <NUM> can otherwise pass through or under the wound cover <NUM> to supply reduced pressure to the wound cavity <NUM> so as to maintain a desired level of reduced pressure in the wound cavity. The conduit <NUM> can be any suitable article configured to provide at least a substantially sealed fluid flow pathway between the pump assembly <NUM> and the wound cover <NUM>, so as to supply the reduced pressure provided by the pump assembly <NUM> to wound cavity <NUM>. The wound cover <NUM> and the wound filler <NUM> can be provided as a single article or an integrated single unit. In some embodiments, no wound filler is provided and the wound cover by itself may be considered the wound dressing. The wound dressing may then be connected, via the conduit <NUM>, to a source of negative pressure, such as the pump assembly <NUM>. The pump assembly <NUM> can be miniaturized and portable, although larger conventional pumps such can also be used.

The wound cover <NUM> can be located over a wound site to be treated. The wound cover <NUM> can form a substantially sealed cavity or enclosure over the wound site. In some embodiments, the wound cover <NUM> can be configured to have a film having a high water vapour permeability to enable the evaporation of surplus fluid, and can have a superabsorbing material contained therein to safely absorb wound exudate. It will be appreciated that throughout this specification reference is made to a wound. In this sense 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 surficial 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, acute wounds, chronic wounds, surgical incisions and other incisions, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stoma, surgical wounds, trauma and venous ulcers or the like. The components of the TNP system described herein can be particularly suited for incisional wounds that exude a small amount of wound exudate.

Some embodiments of the system are designed to operate without the use of an exudate canister. Some embodiments can be configured to support an exudate canister. In some embodiments, configuring the pump assembly <NUM> and tubing <NUM> so that the tubing <NUM> can be quickly and easily removed from the pump assembly <NUM> can facilitate or improve the process of dressing or pump changes, if necessary. Any of the pump embodiments disclosed herein can be configured to have any suitable connection between the tubing and the pump.

In some embodiments, the pump assembly <NUM> can be configured to deliver negative pressure of approximately -<NUM> mmHg, or between about -<NUM> mmHg and -<NUM> mmHg. Note that these pressures are relative to normal ambient atmospheric pressure thus, -<NUM> mmHg would be about <NUM> mmHg in practical terms. 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 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 pump assembly <NUM>. In some embodiments, the pump assembly <NUM> is configured to provide continuous or intermittent negative pressure therapy. Continuous therapy can be delivered at above -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, - <NUM> mmHg, -<NUM> mmHg, or below -<NUM> mmHg. Intermittent therapy can be delivered between low and high negative pressure setpoints. Low setpoint can be set at above <NUM> mmHg, <NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, or below -<NUM> mmHg. High setpoint can be set at above -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, -<NUM> mmHg, or below -<NUM> mmHg. During intermittent therapy, negative pressure at low setpoint can be delivered for a first-time duration, and upon expiration of the first-time duration, negative pressure at high setpoint can be delivered for a second-time duration. Upon expiration of the second-time duration, negative pressure at low setpoint can be delivered. The first and second time durations can be same or different values. The first and second durations can be selected from the following range: less than <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, <NUM> minutes, or greater than <NUM> minutes. In some embodiments, switching between low and high setpoints and vice versa can be performed according to a step waveform, square waveform, sinusoidal waveform, and the like.

In some embodiments, the TNP system <NUM> can include multiple wound dressings connected to the pump assembly <NUM>. The performance and wound healing capabilities (such as, fluid management) of the TNP system with multiple wound dressings with the pump assembly <NUM> can be equivalent to or exceed that of a standard single wound dressing with single pump set-up.

In operation, the wound filler <NUM> is inserted into the wound cavity <NUM> and wound cover <NUM> is placed so as to seal the wound cavity <NUM>. The pump assembly <NUM> provides a source of a negative pressure to the wound cover <NUM>, which is transmitted to the wound cavity <NUM> via the wound filler <NUM>. Fluid (e.g., wound exudate) is drawn through the conduit <NUM>, and can be stored in a canister. In some embodiments, fluid is absorbed by the wound filler <NUM> or one or more absorbent layers (not shown).

Wound dressings that may be utilized with the pump assembly and other embodiments of the present application include Renasys-F, Renasys-G, Renasys AB, and Pico Dressings available from Smith & Nephew. Any of the dressings described herein can be used with Smith and Nephew's Renasys Soft Port connector or interface between the dressing and the pump assembly. For example, the Renasys Soft Port connector can be positioned in the flow path <NUM> and serve as a port for the wound dressing. In other embodiments, other suitable wound dressings can be utilized.

<FIG> illustrates a front view <NUM> of a pump assembly <NUM> and canister <NUM> according to some embodiments. As is illustrated, the pump assembly <NUM> and the canister may be connected, thereby forming a TNP device or system. The pump assembly <NUM> may include one or more indicators, such as visual indicator <NUM> configured to indicate alarms and visual indicator <NUM> configured to indicate status of the TNP system. The indicators <NUM> and <NUM> can be configured to alert a user, such as patient or medical care provider, to a variety of operating or failure conditions of the system, including alerting the user to normal or proper operating conditions, pump failure, power supplied to the pump or power failure, detection of a leak within the wound cover or flow pathway, suction blockage, no flow condition, canister full condition, or any other similar or suitable conditions or combinations thereof. The pump assembly <NUM> can include additional indicators. The pump assembly can use a single indicator or multiple indicators. Any suitable indicator can be used such as visual, audio, tactile indicator, and so on. The indicator <NUM> can be configured to signal alarm conditions, such as canister full, power low, conduit <NUM> disconnected, seal broken in the wound seal <NUM>, and so on. The indicator <NUM> can be configured to display red flashing light to draw user's attention. The indicator <NUM> can be configured to signal status of the TNP system, such as therapy delivery is ok, leak detected, and so on. The indicator <NUM> can be configured to display one or more different colors of light, such as green, yellow, etc. For example, green light can be emitted when the TNP system is operating properly and yellow light can be emitted to indicate a warning.

The pump assembly <NUM> may include a display or screen <NUM> mounted in a recess <NUM> formed in a case of the pump assembly. The display <NUM> can be a touch screen display. The display <NUM> can support playback of audiovisual (AV) content, such as instructional videos. As explained herein, the display <NUM> can be configured to render a number of screens or graphical user interfaces (GUIs) for configuring, controlling, and monitoring the operation of the TNP system. The pump assembly <NUM> includes a gripping portion <NUM> formed in the case of the pump assembly. The gripping portion <NUM> can be configured to assist the user to hold the pump assembly <NUM>, such as during removal of the canister <NUM>. The canister <NUM> can be replaced with another canister, such as when the canister <NUM> has been filled with fluid.

The pump assembly <NUM> may include one or more keys or buttons <NUM> configured to allow the user to operate and monitor the operation of the TNP system. As is illustrated, there buttons 212a, 212b, and 212c are included. Button 212a can be configured as a power button to turn on/off the pump assembly <NUM>. Button 212b can be configured as a play/pause button for the delivery of negative pressure therapy. For example, pressing the button 212b can cause therapy to start, and pressing the button 212b afterward can cause therapy to pause or end. Button 212c can be configured to lock the display <NUM> or the buttons <NUM>. For instance, button 212c can be pressed so that the user does not unintentionally alter the delivery of the therapy. Button 212c can be depressed to unlock the controls. In other embodiments, additional buttons can be used or one or more of the illustrated buttons 212a, 212b, or 212c can be omitted. Multiple key presses or sequences of key presses can be used to operate the pump assembly <NUM>.

The pump assembly <NUM> may include one or more latch recesses <NUM> formed in the cover. In the illustrated embodiment, two latch recesses <NUM> can be formed on the sides of the pump assembly <NUM>. The latch recesses <NUM> can be configured to allow attachment and detachment of the canister <NUM> using one or more canister latches <NUM>. The pump assembly <NUM> includes an air outlet <NUM> for allowing air removed from the wound cavity <NUM> to escape. Air entering the pump assembly can be passed through one or more suitable filters, such as antibacterial filters. This can maintain reusability of the pump assembly. The pump assembly <NUM> includes one or more strap mounts <NUM> for connecting a carry strap to the pump assembly <NUM> or for attaching a cradle. In the illustrated embodiment, two strap mounts <NUM> can be formed on the sides of the pump assembly <NUM>. In some embodiments, various features are omitted or various additional features are added to the pump assembly <NUM>.

The canister <NUM> may be configured to hold fluid (e.g., exudate) removed from the wound cavity <NUM>. The canister <NUM> may include one or more latches <NUM> for attaching the canister to the pump assembly <NUM>. In the illustrated embodiment, the canister <NUM> includes two latches <NUM> on the sides of the canister. The exterior of the canister <NUM> can formed from frosted plastic so that the canister is substantially opaque and the contents of the canister and substantially hidden from plain view. The canister <NUM> may include a gripping portion <NUM> formed in a case of the canister. The gripping portion <NUM> can be configured to allow the user to hold the pump assembly <NUM>, such as during removal of the canister from the apparatus <NUM>. The canister <NUM> includes a substantially transparent window <NUM>, which can also include graduations of volume. For example, the illustrated <NUM> canister <NUM> includes graduations of <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>. Other embodiments of the canister can hold different volume of fluid and can include different graduation scale. For example, the canister can be an <NUM> canister. The canister <NUM> includes a tubing channel <NUM> for connecting to the conduit <NUM>. In some embodiments, one or more of these features, such as the gripping portion <NUM>, are omitted or various additional features are added to the canister <NUM>. Any of the disclosed canisters may include or may omit a solidifier.

<FIG> illustrates an electrical component schematic <NUM> of a pump assembly, such as the pump assembly <NUM>, according to some embodiments. Electrical components can operate to accept user input, provide output to the user, operate the pump assembly and the TNP system, provide network connectivity, and so on. Electrical components can be mounted on one or more printed circuit boards (PCBs). As is illustrated, the pump assembly can include multiple processors. It may be advantageous to utilize multiple processors in order to allocate or assign various tasks to different processors. A first processor can be responsible for user activity and a second processor can be responsible for controlling the pump. This way, the activity of controlling the pump, which may necessitate a higher level of responsiveness (corresponding to higher risk level), can be offloaded to a dedicated processor and, thereby, will not be interrupted by user interface tasks, which may take longer to complete because of interactions with the user.

The pump assembly can include a user interface processor or controller <NUM> configured to operate one or more components for accepting user input and providing output to the user, such as the display <NUM>, buttons <NUM>, etc. Input to the pump assembly and output from the pump assembly can controlled by an input/output (I/O) module <NUM>. For example, the I/O module can receive data from one or more ports, such as serial, parallel, hybrid ports, and the like. The processor <NUM> also receives data from and provides data to one or more expansion modules <NUM>, such as one or more USB ports, SD ports, Compact Disc (CD) drives, DVD drives, FireWire ports, Thunderbolt ports, PCI Express ports, and the like. The processor <NUM>, along with other controllers or processors, stores data in one or more memory modules <NUM>, which can be internal or external to the processor <NUM>. Any suitable type of memory can be used, including volatile or non-volatile memory, such as RAM, ROM, magnetic memory, solid-state memory, Magnetoresistive random-access memory (MRAM), and the like.

In some embodiments, the processor <NUM> can be a general-purpose controller, such as a low-power processor. In other embodiments, the processor <NUM> can be an application specific processor. The processor <NUM> can be configured as a "central" processor in the electronic architecture of the pump assembly, and the processor <NUM> can coordinate the activity of other processors, such as a pump control processor <NUM>, communications processor <NUM>, and one or more additional processors <NUM> (e.g., processor for controlling the display <NUM>, processor for controlling the buttons <NUM>, etc.). The processor <NUM> can run a suitable operating system, such as a Linux, Windows CE, VxWorks, etc..

The pump control processor <NUM> can be configured to control the operation of a negative pressure source or pump <NUM>. The pump <NUM> can be a suitable pump, such as a diaphragm pump, peristaltic pump, rotary pump, rotary vane pump, scroll pump, screw pump, liquid ring pump, pump (for example, diaphragm pump) operated by a piezoelectric transducer, voice coil pump, and the like. The pump control processor <NUM> can measure pressure in a fluid flow path, using data received from one or more pressure sensors, calculate the rate of fluid flow, and control the pump. The pump control processor <NUM> can control an actuator, such as a pump motor, so that a desired level of negative pressure is achieved in the wound cavity <NUM>. The desired level of negative pressure can be pressure set or selected by the user. In various embodiments, the pump control processor <NUM> controls the pump actuator (e.g., pump motor) using pulse-width modulation (PWM). A control signal for driving the pump actuator can be a <NUM>-<NUM>% duty cycle PWM signal. The pump control processor <NUM> can perform flow rate calculations and detect various conditions in a flow path. The pump control processor <NUM> can communicate information to the processor <NUM>. The pump control processor <NUM> can include internal memory or can utilize memory <NUM>. The pump control processor <NUM> can be a low-power processor.

A communications processor <NUM> can be configured to provide wired or wireless connectivity. The communications processor <NUM> can utilize one or more antennas <NUM> for sending and receiving data. The communications processor <NUM> can provide one or more of the following types of connections: Global Positioning System (GPS) technology, cellular connectivity (e.g., <NUM>, <NUM>, LTE, <NUM>), Wi-Fi connectivity, Internet connectivity, and the like. Connectivity can be used for various activities, such as pump assembly location tracking, asset tracking, compliance monitoring, remote selection, uploading of logs, alarms, and other operational data, and adjustment of therapy settings, upgrading of software or firmware, and the like. The communications processor <NUM> can provide dual GPS/cellular functionality. Cellular functionality can, for example, be <NUM> functionality. In such cases, if the GPS module is not able to establish satellite connection due to various factors including atmospheric conditions, building or terrain interference, satellite geometry, and so on, the device location can be determined using the <NUM> network connection, such as by using cell identification, triangulation, forward link timing, and the like. The pump assembly can include a SIM card, and SIM-based positional information can be obtained.

The communications processor <NUM> can communicate information to the processor <NUM>. The communications processor <NUM> can include internal memory or can utilize memory <NUM>. The communications processor <NUM> can be a low-power processor.

In some embodiments, the pump assembly can track and store various data, such as one or more of positioning data, therapy parameters, logs, device data, and so on. The pump assembly can track and log therapy and other operational data. Data can be stored, for example, in the memory <NUM>.

In some embodiments, using the connectivity provided by the communications processor <NUM>, the device can upload any of the data stored, maintained, or tracked by the pump assembly. For example, the following information can be uploaded to a remote computer or server: activity log(s), which includes therapy delivery information, such as therapy duration, alarm log(s), which includes alarm type and time of occurrence; error log, which includes internal error information, transmission errors, and the like; therapy duration information, which can be computed hourly, daily, and the like; total therapy time, which includes therapy duration from first applying a particular therapy program or programs; lifetime therapy information; device information, such as the serial number, software version, battery level, etc.; device location information; patient information; and so on. The device can also download various operational data, such as therapy selection and parameters, firmware and software patches and upgrades, and the like. The pump assembly can provide Internet browsing functionality using one or more browser programs, mail programs, application software (e.g., apps), etc..

In some embodiments, the communications processor <NUM> can use the antenna <NUM> to communicate a location of the pump assembly, such as a location of a housing of the pump assembly, to other devices in the proximity (for example, within <NUM>, <NUM>, or <NUM> meters and the like) of the pump assembly. The communications processor <NUM> can perform one-way or two-way communication with the other devices depending on the implementation. The communications transmitted by the communications processor <NUM> can include identifying information to uniquely identify the pump assembly relative to one or more other pump assemblies also in the proximity of the pump assembly. For example, identifying information can include a serial number or a value derived from the serial number. The signal strength of the transmitted communications by the communications processor <NUM> can be controlled (for example, maintained at a constant or substantially constant level) to enable another device to determine a distance to the pump assembly, such as a distance between the device and the pump assembly.

In some embodiments, the communications processor <NUM> can communicate with other devices in the proximity of the pump assembly so that the communications processor <NUM> can itself determine a distance from the pump assembly to the other devices. The communications processor <NUM>, in such embodiments, can track and store the distance from the pump assembly to the other devices or indications of change in the distance over time, and the communications processor <NUM> can later provide this information to the other devices. For instance, the communications processor <NUM> can determine a duration of time during which the pump assembly has been removed from a coverage area of a device and subsequently report this time to the device upon being returned to the coverage area.

<FIG> illustrate embodiments of a negative pressure wound treatment system <NUM> similar to the embodiment illustrated in <FIG>. Here, the system <NUM> may comprise a flexible suction adapter <NUM> having a bridge portion <NUM> with a proximal end <NUM> and a distal end <NUM>, and an applicator <NUM> at the distal end <NUM> of the bridge portion <NUM> forming the flexible suction adapter <NUM>. A connector <NUM> is preferably disposed at the proximal end <NUM> of the bridge portion <NUM>, so as to connect to at least one of the channels <NUM> and/or <NUM>, as shown in <FIG>. A cap <NUM> may be provided with the system <NUM> (and can in some cases, as illustrated, be attached to the connector <NUM>). The cap <NUM> can be useful in preventing fluids from leaking out of the proximal end <NUM>. The system <NUM> may include a source of negative pressure such as a pump or negative pressure unit <NUM> capable of supplying negative pressure. The pump also preferably comprises a canister or other container for the storage of wound exudates and other fluids that may be removed from the wound. In some embodiments, this pump <NUM> may be the pump <NUM> described in relation to <FIG>. In some embodiments, this pump <NUM> can be a RENASYS GO pump, as sold by Smith & Nephew. The pump <NUM> may be connected to the connector <NUM> via a tube <NUM>. In use, the applicator <NUM> is placed over an aperture <NUM> formed in a drape <NUM> that is placed over a suitably-prepared wound <NUM>, which may in some cases be filled with a wound packing material such as foam or gauze. Subsequently, with the pump <NUM> connected via the tube <NUM> to the connector <NUM>, the pump is activated, thereby supplying negative pressure to the wound. Application of negative pressure may be applied until a desired level of healing of the wound <NUM> is achieved.

In some embodiments, the bridge portion <NUM> may comprise an upper channel layer <NUM> positioned between an upper layer <NUM> and an intermediate layer <NUM>, with a lower channel layer <NUM> positioned between the intermediate layer <NUM> and a bottom layer <NUM>. Preferably, the layers <NUM>, <NUM>, and <NUM> have elongate portions extending between proximal and distal ends and may be comprised of a material that is fluid-impermeable, for example polymers such as polyurethane. It will of course be appreciated that the layers <NUM>, <NUM>, and <NUM> may each be constructed from different materials, including semi-permeable materials. In some embodiments, one or more of the layers <NUM>, <NUM>, and <NUM> may be at least partially transparent. As illustrated in <FIG>, the upper and lower layers <NUM> and <NUM> may be curved, rounded or outwardly convex over a majority of their lengths. During assembly, for example, the layers <NUM>, <NUM>, and <NUM> may be pinched together to weld or adhere the layers together. In doing so, the proximal ends of the channels <NUM> and <NUM> may be sandwiched between these layers, thus partially compressing the proximal ends of the channels <NUM>, <NUM> and stretching the layers <NUM>, <NUM>, <NUM> over these aforementioned proximal ends. Of course, the proximal ends of the materials used in the bridge portion <NUM> may not necessarily be rounded or curved; as shown in <FIG>, they can remain substantially squared off and straight.

The upper and lower channel layers <NUM> and <NUM> are preferably elongate layers extending from the proximal end <NUM> to the distal end <NUM> and may each preferably comprise a porous material, including for example open-celled foams such as polyethylene or polyurethane. In some embodiments, one or more of the upper and lower channel layers <NUM> and <NUM> may be comprised of a fabric, for example a knitted or woven spacer fabric (such as a knitted polyester 3D fabric, Baltex <NUM>. , or Gehring <NUM>. ) or a nonwoven material. Suitable materials may also include terry-woven or loop-pile materials. The fibers may not necessarily be woven, and can include felted and flocked (including materials such as Flotex. ) fibrous materials. The materials selected are preferably suited to channeling wound exudate away from the wound and for transmitting negative pressure and/or vented air to the wound site, and may also confer a degree of kinking or occlusion resistance to the channel layers <NUM> and <NUM> as described below. In one embodiment, the upper channel layer <NUM> may comprise an open-celled foam such as polyurethane, and the lower channel layer may comprise a fabric as described herein. In another embodiment, the upper channel layer is optional, and the system may instead be provided with an open upper channel. In the embodiment illustrated in <FIG>, the upper channel layer <NUM> may have a curved, rounded or upwardly convex upper surface and a substantially flat lower surface, and the lower channel layer <NUM> may have a curved, rounded or downwardly convex lower surface and a substantially flat upper surface.

In some embodiments, the fabric may have a three-dimensional (3D) structure, where one or more types of fibers form a structure where the fibers extend in all three dimensions. Such a fabric may in some cases aid in wicking, transporting fluid, and/or transmitting negative pressure. To prevent the channels <NUM> and/or <NUM> from being displaced or twisted while encased in the system <NUM>--which may impair performance of the respective channels under negative pressure--it may in some embodiments be preferable to adhere or otherwise secure the channels <NUM> and/or <NUM> to one or more of the layers <NUM>, <NUM>, and <NUM>. In certain embodiments, these materials remain open and capable of communicating negative pressure to a wound area under the typical pressures used in negative pressure therapy, for example between <NUM> to <NUM> mmHg, although higher and lower values are possible. In some embodiments, the fabric may comprise several layers of material stacked or layered over each other, which may in some cases be useful in preventing the channel <NUM> from collapsing under the application of negative pressure. In other embodiments, the fabric used in channel <NUM> may be between <NUM> and <NUM>; more preferably, the fabric may be between <NUM> and <NUM> thick, and may be comprised of either one or several individual layers of fabric. In other embodiments, the channel <NUM> may be between <NUM>-<NUM> thick, and preferably thicker than <NUM>. Additionally, and as described previously, the materials used in the system <NUM> are preferably conformable and soft, which may help to avoid pressure ulcers and other complications which may result from a wound treatment system being pressed against the skin of a patient. Further examples of 3D fabrics are discussed below in <FIG>.

Preferably, the distal ends of the layers <NUM>, <NUM>, and <NUM> and the channel layers <NUM> and <NUM> are enlarged at their distal ends (to be placed over a wound site), and may form a "teardrop" or other enlarged shape. The distal ends of at least the layers <NUM>, <NUM>, <NUM>, and <NUM> may also be provided with at least one through aperture. This aperture may be useful not only for the drainage of wound exudate and for applying negative pressure to the wound, but also during manufacturing of the device, as these apertures may be used to align these respective layers appropriately.

With additional reference to <FIG> and <FIG>, a channel connector <NUM> is provided at the proximal end <NUM> of the bridge portion <NUM>, the channel connector <NUM> preferably being configured so as to be embedded into the lower channel layer <NUM> so as to create a secure fluidic connection. The channel connector <NUM> may in some embodiments be inserted into a pre-made cavity formed into the channel <NUM>; as illustrated in <FIG>, this cavity can be cut out or can be in the form of a rabbet joint. In some embodiments, the channel connector <NUM> may be one of the connectors described in <FIG> below. With one end of the channel connector <NUM> being embedded into the lower channel layer <NUM>, the other end of the channel connector <NUM> may be connected or in communication with, in one embodiment, a connector tube <NUM>, although in some embodiments the channel connector <NUM> may be connected directly to the connector <NUM>, or else connected directly to a tube <NUM> connected to a source of negative pressure. When using a connector tube <NUM>, the resulting assembly can permit a connector <NUM> to be attached thereto. A cap <NUM>, which may be secured to the suction adapter for example via a cap leash <NUM> secured with a ring disposed on the outer surface of the connector tube <NUM>. The cap <NUM> may be used to cover the end of the suction adapter, for example at the connector <NUM>, so as to prevent exudate and other wound fluids from leaking out. The connector <NUM> is preferably configured to connect with a tube <NUM> connected to a source of negative pressure. The connector <NUM> may for example comprise a lip or other such structure to aid in securing the connector <NUM> to a tube <NUM> and/or cap <NUM>, although it will be understood that other connector types are possible, including quick-disconnect couplings, luer locks, Christmas-tree, and other such connectors.

The upper layer <NUM> may comprise additional material extending downward, preferably at least of the thickness of the bridge portion <NUM>; this material may then be used to bond or weld to the other layers so to form a fluid-tight seal. More specifically, during assembly, the upper layer <NUM> may be attached, for example by melting, welding, or with adhesives, to the lower layer <NUM> so as to form a fluid-tight seal (with the exception of the apertures at the distal and proximal ends). Preferably, the middle layer <NUM> is attached to the top layer <NUM> and the bottom layer <NUM>. In some embodiments, it may be preferable to attach or bond the connectors <NUM> and/or <NUM>, as well as the tube <NUM> to at least one of the layers <NUM>, <NUM>, <NUM> so as to create a fluid-tight connection. To provide for a more secure connection, some embodiments may also be provided with a weld <NUM> made onto the lower layer <NUM>. The lower channel <NUM> may have a hole or aperture made through it, which may be used to weld it, via the weld <NUM>, to the lower layer <NUM>. This welding of the lower channel <NUM> to the lower layer <NUM> via the weld <NUM> made through the hole <NUM> may thus aid in preventing the various layers and channels from shifting or being displaced. Obviously, it will be understood that other securement means may be used, for example adhesives and the like, and that such arrangements may be also be used in the upper channel <NUM>.

In certain embodiments, for example as illustrated in <FIG>, a controlled air leak <NUM> may be disposed on the bridge portion <NUM>, for example at the proximal end thereof. This air leak <NUM> may comprise an opening or channel extending through upper layer <NUM>, such that the air leak <NUM> is in fluidic communication with the upper channel <NUM>. Upon the application of suction to the suction adapter <NUM>, air will enter through the air leak <NUM> and move from the proximal end <NUM> to the distal end <NUM> along the upper channel <NUM>. The air will then be suctioned into the lower channel <NUM> by passing through the apertures through the distal ends of the layers <NUM>, <NUM>, <NUM> and <NUM>. The air leak <NUM> preferably comprises a filter <NUM>. Preferably, the air leak <NUM> is located at the proximal end of the bridge portion <NUM> so as to minimize the likelihood of wound exudate or other fluids coming into contact and possibly occluding or interfering with the air leak <NUM> or its filter <NUM>. In some embodiments, this filter <NUM> is a microporous membrane capable of excluding microorganisms and bacteria, and which may be able to filter out particles larger than <NUM>. Preferably, the filter <NUM> can exclude particles larger than <NUM>, and more preferably, particles larger than <NUM>. Advantageously, some embodiments may provide for a filter <NUM> that is at least partially chemically-resistant, for example to water, common household liquids such as shampoos, and other surfactants. In some embodiments, reapplication of vacuum to the suction adapter <NUM> and/or wiping of the exposed outer portion of the filter <NUM> may be sufficient to clear any foreign substance occluding the filter <NUM>. The filter <NUM> may be composed of a suitably-resistant polymer such as acrylic, polyethersulfone, or polytetrafluoroethylene, and may be oleophobic and/or hydrophobic. In some embodiments, the filter <NUM> may also comprise a supporting backing layer, for example a nonwoven polyester support. Preferably, the air leak <NUM> will supply a relatively constant air flow that does not appreciably increase as additional negative pressure is applied to the system <NUM>. In embodiments of the suction adapter <NUM> where the air flow through the air leak <NUM> increases as additional negative pressure is applied, preferably this increased air flow will be minimized and not increase in proportion to the negative pressure applied thereto.

The filter <NUM> provided in the controlled air leak <NUM> in certain embodiments may be useful in a system <NUM> for use with more ambulatory and active patients. For example, a chemically-resistant filter may permit a patient to bathe or shower without damaging the filter's functionality when reconnected to a source of negative pressure. Any occlusion or fluid blocking the air leak <NUM> could then be cleared by, for example, wiping off the filter <NUM> or re-applying negative pressure to the suction adapter <NUM>. Such a system would also have the advantage that the system <NUM> and any assorted wound dressing materials, if present, would not need to be removed and then re-applied should a patient need to be disconnected from the source of negative pressure, for example incidental to bathing. This would entail significant advantages in improving the cost-effectiveness and ease of use of the present treatment system.

The suction adapter <NUM> is preferably constructed so as to provide a consistent fluid flow even if the suction adapter <NUM> is kinked or weighted down. For example, in use on a patient, the bridge portion <NUM> may become folded over itself, or else the patient may roll over, thus placing his or her weight over at least a portion of the suction adapter <NUM>. Typically, prior art dressings and fluidic connectors become blocked or ineffective in such situations and in some cases may contribute to complications such as pressure ulcers. Here, however, certain embodiments provide for improved blockage resistance if kinked or weighed down. Preferably, by employing channel layers <NUM> and <NUM> as described above, and more preferably by employing a foam channel layer <NUM> and a fabric channel layer <NUM>, the suction adapter <NUM> is able to maintain a flow rate through the air leak <NUM> of at least <NUM>/min, and preferably <NUM>/min while negative pressure is applied through a source of negative pressure. Further embodiments also provide for the suction adapter <NUM> to be able to handle fluid exudate drainage from the wound site through the lower channel <NUM> of at least <NUM>/day, or <NUM>/min. Certain embodiments provide for the suction adapter <NUM> to maintain these flow rates with a weight, for example a <NUM> weight, pressing down on the bridge portion through a rod with a <NUM> in. In some embodiments, these flow rates are also maintained while the bridge portion <NUM> is kinked over itself with the same weight, or for example with a <NUM> weight placed directly on the folded region. It is preferable that the suction adapter <NUM> be able to withstand being folded or kinked over even during an extended period of time, for example over <NUM> hours, and not show any degradation in performance (e.g., flow rates) compared to its performance prior to being folded or kinked over. Preferably, embodiments of the suction adapter <NUM> are also able to transmit and maintain a negative pressure at the wound that is close to the negative pressure level at the source of negative pressure. For example, an acceptable level of pressure maintained at the wound may be within +-. <NUM> mmHg of the negative pressure set at the source of negative pressure, with this pressure being preferably maintained at this level within <NUM>% of the time that the suction adapter <NUM> has negative pressure applied to it. Acceptable pressure levels may include pressure ranges between <NUM>-<NUM> mmHg, although levels of <NUM> mmHg have successfully been used.

With additional reference to <FIG> and <FIG>, the suction adapter <NUM> also comprises an applicator <NUM> designed for placement over a wound site. Preferably, the applicator <NUM> comprises a flexible layer <NUM>, for example polyethylene or polyurethane, with a layer of adhesive on its lower (wound-facing) side. Optionally, a protective release layer <NUM> may be placed on the adhesive layer, which is removable before use. In some embodiments, a more rigid removable backing layer <NUM> may be provided on the upper side of the applicator <NUM> to facilitate handling of the applicator <NUM> due to the flexibility of the layer <NUM>. The applicator <NUM> preferably comprises an attachment point for the bridge <NUM> at the distal end <NUM>, for example using a section of double-sided adhesive tape <NUM>. The double-sided adhesive tape <NUM> may be protected by an additional protective release layer, which is removed prior to adhering the bridge <NUM> to the applicator <NUM>. It will be understood that different attachment methods are also contemplated, for example heat sealing, welding, or suitable adhesives. Some embodiments may also permit the manufacture of the bridge <NUM> and the applicator <NUM> as a single unit that does not require separate attachment means. The applicator <NUM> preferably comprises at least one aperture <NUM> through itself and designed to be placed over a wound site, and which can serve to fluidically connect the wound site to the source of negative pressure and to the air leak while also serving as a conduit to draw out wound exudate from the wound site.

In use, and with reference to <FIG>, the system <NUM> may be used in a similar fashion to the other embodiments previously disclosed herein, such as the system <NUM> described in relation to <FIG>. A wound site <NUM> is preferably cleaned and prepared in a suitable fashion, and a wound packing material, if necessary, placed into the wound site, followed by a drape <NUM>. An aperture <NUM> through the drape to the wound site is then created, although some embodiments may have a pre-made aperture <NUM>. Subsequently, an operator may situate the applicator portion <NUM> over the aperture <NUM>. After removing the backing layer <NUM> (if present) from the adhesive layer on the underside of the applicator portion <NUM>, the applicator is sealed to the drape <NUM>, and the backing layer <NUM> (if present) is also removed from the applicator portion <NUM>. A fluidic conduit such as a tube <NUM> may then be connected to the connector <NUM>. The tube <NUM> may also be connected to connector <NUM> prior to applying the applicator to the wound site. The fluidic conduit is connected to a source of negative pressure <NUM>, preferably with a container suitable for containing wound exudate interposed therebetween. The application of negative pressure may then be effectuated to the wound site <NUM> until the wound site progresses to a desired level of healing.

During use of the system <NUM>, wound exudate from the wound site <NUM> is drawn by the negative pressure through the lower channel layer <NUM>. The air leak <NUM> allows air to pass through the upper channel layer <NUM> into the apertures through the distal ends of the layers <NUM>, <NUM>, <NUM> and <NUM>. The negative pressure draws air passing through the upper channel layer into the lower channel layer <NUM> back toward the source of negative pressure or pump. In some embodiments, the controlled air leak <NUM> provides a constant flow of air through the suction adapter <NUM>, which then may be used to determine whether blockage or leakage is present. Causes of blockage can include, for example, situations where the lower channel <NUM> becomes occluded with wound debris. Leakage causes can include, for example, improper sealing of the drape over the wound site, or physical damage to the suction adapter <NUM> leading to excess air leaking into the system. The blockage or leakage may be determined, in certain embodiments, by measuring the speed of the pump while the pump works to maintain a constant negative pressure. Pump speed may also be measured indirectly by measuring the amount of voltage or signal sent to the pump.

<FIG> illustrates an embodiment of a negative pressure wound treatment system <NUM> employing a wound dressing <NUM> in conjunction with a fluidic connector <NUM>. Additional examples related to negative pressure wound treatment comprising a wound dressing in combination with a pump as described herein may also be used in combination or in addition to those described in <CIT>, which is incorporated by reference in its entirety. Here, the fluidic connector <NUM> may comprise an elongate conduit, more preferably a bridge <NUM> having a proximal end <NUM> and a distal end <NUM>, and an applicator <NUM> at the distal end <NUM> of the bridge <NUM>. The system <NUM> may include a source of negative pressure such as a pump or negative pressure unit <NUM> capable of supplying negative pressure. The pump may comprise a canister or other container for the storage of wound exudates and other fluids that may be removed from the wound. A canister or container may also be provided separate from the pump. In some embodiments, the pump <NUM> can be a canisterless pump such as the PICO™ pump, as sold by Smith & Nephew. The pump <NUM> may be connected to the bridge <NUM> via a tube, or the pump <NUM> may be connected directly to the bridge <NUM>. In use, the dressing <NUM> is placed over a suitably-prepared wound, which may in some cases be filled with a wound packing material such as foam or gauze as described above. The applicator <NUM> of the fluidic connector <NUM> has a sealing surface that is placed over an aperture in the dressing <NUM> and is sealed to the top surface of the dressing <NUM>. Either before, during, or after connection of the fluidic connector <NUM> to the dressing <NUM>, the pump <NUM> is connected via the tube to the coupling <NUM>, or is connected directly to the bridge <NUM>. The pump is then activated, thereby supplying negative pressure to the wound. Application of negative pressure may be applied until a desired level of healing of the wound is achieved.

As shown in <FIG>, the fluidic connector <NUM> preferably comprises an enlarged distal end, or head <NUM> that is in fluidic communication with the dressing <NUM> as will be described in further detail below. In one embodiment, the enlarged distal end has a round or circular shape. The head <NUM> is illustrated here as being positioned near an edge of the dressing <NUM>, but may also be positioned at any location on the dressing. For example, some embodiments may provide for a centrally or off-centered location not on or near an edge or corner of the dressing <NUM>. In some embodiments, the dressing <NUM> may comprise two or more fluidic connectors <NUM>, each comprising one or more heads <NUM>, in fluidic communication therewith. In a preferred embodiment, the head <NUM> may measure <NUM> along its widest edge. The head <NUM> forms at least in part the applicator <NUM>, described above, that is configured to seal against a top surface of the wound dressing.

<FIG> illustrates a cross-section through a wound dressing <NUM> similar to the wound dressing <NUM> as described in International Patent Publication <CIT>, which is incorporated by reference in its entirety, along with fluidic connector <NUM>. The wound dressing <NUM>, which can alternatively be any wound dressing embodiment disclosed herein or any combination of features of any number of wound dressing embodiments disclosed herein, can be located over a wound site to be treated. The dressing <NUM> may be placed as to form a sealed cavity over the wound site. In a preferred embodiment, the dressing <NUM> comprises a top or cover layer, or backing layer <NUM> attached to an optional wound contact layer <NUM>, both of which are described in greater detail below. These two layers <NUM>, <NUM> are preferably joined or sealed together so as to define an interior space or chamber. This interior space or chamber may comprise additional structures that may be adapted to distribute or transmit negative pressure, store wound exudate and other fluids removed from the wound, and other functions which will be explained in greater detail below. Examples of such structures, described below, include a transmission layer <NUM> and an absorbent layer <NUM>.

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.

As illustrated in <FIG>, 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 <NUM> and an upper surface <NUM>. The perforations <NUM> 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 <NUM> of the wound dressing <NUM> whilst an upper pressure sensitive adhesive layer may be provided on the upper surface <NUM> 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 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 transmission layer <NUM> can be located above the wound contact layer <NUM>. In some embodiments, the transmission layer can be a porous material. As used herein the transmission layer can be referred to as a spacer layer and the terms can be used interchangeably to refer to the same component described herein. This 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 three-dimensional material can comprise a 3D spacer fabric material similar to the material described in International Publication <CIT> and International Publication <CIT>, the disclosures of which are incorporated by reference in their entireties.

In certain embodiments, the wound dressing <NUM> may incorporate or comprise a multi-care WCL as described herein this section or elsewhere in the specification. One of skill in the art will understand that the wound dressing <NUM> may incorporate any of the multi-care WCLs disclosed herein this section or elsewhere in the specification. One of skill in the art will also understand that the multi-care WCL may be incorporated as a whole component layer or a part of a component layer. In some embodiments, the multi-care WCL layer may be provided below the transmission layer <NUM>. In some embodiments, the multi-care WCL layer may be provided above the wound contact layer <NUM>. In some embodiments, the multi-care WCL layer may replace the transmission layer <NUM>, such that the multi-care WCL layer is provided between an absorbent layer <NUM> (described further below) and the wound contact layer <NUM>. In some embodiments, the multi-care WCL layer can supplement or replace the absorbent layer <NUM>. In some embodiments, the wound dressing <NUM> does not have the wound contact layer <NUM>, and the multi-care WCL layer may be the lowermost layer of the wound dressing <NUM>. The multi-care WCL may have same or substantially similar size and shape with the transmission layer <NUM> and/or the absorbent layer <NUM>.

The multi-care WCL layer may be constructed to be flexible but stiff enough to withstand negative pressure, such that the multi-care WCL is not collapsed excessively and thereby transmits negative pressure sufficiently to the wound when negative pressure is supplied to the wound dressing <NUM>. The multi-care WCL layer may be constructed to include sufficient number or size of pores to enable transmission of negative pressure through it. Further, the multi-care WCL layer may have suitable thickness to transmit enough negative pressure to the wound. For example, the multi-care WCL layer may have a thickness of <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>, or <NUM> to <NUM>. In some embodiments, the multi-care WCL may have a thickness of approximately <NUM>.

In some embodiments, the layer <NUM> of absorbent material is provided above the transmission layer <NUM>. The absorbent material, which can 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>.

The material of the absorbent layer <NUM> may also prevent liquid collected in the wound dressing <NUM> 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 air-laid, thermally-bonded composite.

An aperture, hole, or orifice <NUM> is preferably provided in the backing layer <NUM> to allow a negative pressure to be applied to the dressing <NUM>. The fluidic connector <NUM> is preferably attached or sealed to the top of the backing layer <NUM> over the orifice <NUM> made into the dressing <NUM>, and communicates negative pressure through the orifice <NUM>. A length of tubing may be coupled at a first end to the fluidic connector <NUM> and at a second end to a pump unit (not shown) to allow fluids to be pumped out of the dressing. Where the fluidic connector is adhered to the top layer of the wound dressing, a length of tubing may be coupled at a first end of the fluidic connector such that the tubing, or conduit, extends away from the fluidic connector parallel or substantially to the top surface of the dressing. The fluidic connector <NUM> may be adhered and sealed to the backing layer <NUM> using an adhesive such as an acrylic, cyanoacrylate, epoxy, UV curable or hot melt adhesive. The fluidic connector <NUM> may be formed from a soft polymer, for example a polyethylene, a polyvinyl chloride, a silicone or polyurethane having a hardness of <NUM> to <NUM> on the Shore A scale. In some embodiments, the fluidic connector <NUM> may be made from a soft or conformable material.

Optionally, the absorbent layer <NUM> includes at least one through hole <NUM> located so as to underlie the fluidic connector <NUM>. The through hole <NUM> may in some embodiments be the same size as the opening <NUM> in the backing layer, or may be bigger or smaller. As illustrated in Figure 2C a single through hole can be used to produce an opening underlying the fluidic connector <NUM>. It will be appreciated that multiple openings could alternatively be utilized. Additionally, should more than one port be utilized according to certain embodiments of the present disclosure one or multiple openings may be made in the absorbent layer in registration with each respective fluidic connector. Although not essential to certain embodiments of the present disclosure the use of through holes in the super-absorbent layer may provide a fluid flow pathway which remains unblocked in particular when the absorbent layer is near saturation.

The aperture or through-hole <NUM> is preferably provided in the absorbent layer <NUM> beneath the orifice <NUM> such that the orifice is connected directly to the transmission layer <NUM> as illustrated in Figure 2C. This allows the negative pressure applied to the fluidic connector <NUM> to be communicated to the transmission layer <NUM> without passing through the absorbent layer <NUM>. This ensures that the negative pressure applied to the wound site is not inhibited by the absorbent layer as it absorbs wound exudates. In other embodiments, no aperture may be provided in the absorbent layer <NUM>, or alternatively a plurality of apertures underlying the orifice <NUM> may be provided. In further alternative embodiments, additional layers such as another transmission layer or an obscuring layer such as described with reference to Figures 6A-6B and in International Patent Publication <CIT>, the entirety of which is hereby incorporated by reference, may be provided over the absorbent layer <NUM> and beneath the backing layer <NUM>.

The backing layer <NUM> is preferably gas impermeable, but moisture vapor permeable, and can extend across the width of the wound dressing <NUM>. The backing 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 backing layer <NUM> and a wound site where a negative pressure can be established. The backing 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 backing 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 backing 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 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 absorbent layer <NUM> may be of a greater area than the transmission layer <NUM>, such that the absorbent layer overlaps the edges of the transmission layer <NUM>, thereby ensuring that the transmission layer does not contact the backing layer <NUM>. This provides an outer channel of the absorbent layer <NUM> that is in direct contact with the wound contact layer <NUM>, which aids more rapid absorption of exudates to the absorbent layer. Furthermore, this outer channel ensures that no liquid is able to pool around the circumference of the wound cavity, which may otherwise seep through the seal around the perimeter of the dressing leading to the formation of leaks. As illustrated in <FIG>, the absorbent layer <NUM> may define a smaller perimeter than that of the backing layer <NUM>, such that a boundary or border region is defined between the edge of the absorbent layer <NUM> and the edge of the backing layer <NUM>.

As shown in <FIG>, one embodiment of the wound dressing <NUM> comprises an aperture <NUM> in the absorbent layer <NUM> situated underneath the fluidic connector <NUM>. In use, for example when negative pressure is applied to the dressing <NUM>, a wound facing portion of the fluidic connector may thus come into contact with the transmission layer <NUM>, which can thus aid in transmitting negative pressure to the wound site even when the absorbent layer <NUM> is filled with wound fluids. Some embodiments may have the backing layer <NUM> be at least partly adhered to the transmission layer <NUM>. In some embodiments, the aperture <NUM> is at least <NUM>-<NUM> larger than the diameter of the wound facing portion of the fluidic connector <NUM>, or the orifice <NUM>.

In particular for embodiments with a single fluidic connector <NUM> and through hole, it may be preferable for the fluidic connector <NUM> and through hole to be located in an off-center position as illustrated in <FIG>. Such a location may permit the dressing <NUM> to be positioned onto a patient such that the fluidic connector <NUM> is raised in relation to the remainder of the dressing <NUM>. So positioned, the fluidic connector <NUM> and the filter <NUM> may be less likely to come into contact with wound fluids that could prematurely occlude the filter <NUM> so as to impair the transmission of negative pressure to the wound site.

Similar to the embodiments of wound dressings described above, some wound dressings comprise a perforated wound contact layer with silicone adhesive on the skin-contact face and acrylic adhesive on the reverse. In some embodiments, the wound contact layer may be constructed from polyurethane, polyethylene or polyester. Above this bordered layer sits a transmission layer. Above the transmission layer, sits an absorbent layer. The absorbent layer can include a superabsorbent non-woven (NW) pad. The absorbent layer can over-border the transmission layer by approximately <NUM> at the perimeter. The absorbent layer can have an aperture or through-hole toward one end. The aperture can be about <NUM> in diameter. Over the transmission layer and absorbent layer lies a backing layer. The backing layer can be a high moisture vapor transmission rate (MVTR) film, pattern coated with acrylic adhesive. The high MVTR film and wound contact layer encapsulate the transmission layer and absorbent layer, creating a perimeter border of approximately <NUM>. The backing layer can have a <NUM> aperture that overlies the aperture in the absorbent layer. Above the hole can be bonded a fluidic connector that comprises a liquid-impermeable, gas-permeable semi-permeable membrane (SPM) or filter that overlies the aforementioned apertures.

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. Additionally, some embodiments related to wound treatment comprising a wound dressing described herein may also be used in combination or in addition to those described in International Application <CIT> and International Patent Application<CIT>, entitled "WOUND TREATMENT APPARATUSES AND METHODS WITH NEGATIVE PRESSURE SOURCE INTEGRATED INTO THE WOUND DRESSING," including further details relating to embodiments of wound dressings, the wound dressing components and principles, and the materials used for the wound dressings and wound dressing components.

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 in the wound dressing 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> and an absorbent area <NUM>. The dressing can comprise a wound contact layer (not shown) 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 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 or transmission layers and/or one or more absorbent layers positioned above the contact layer and below the wound cover layer <NUM> of the dressing.

The dressing can comprise a multi-care WCL, as described above or described elsewhere herein, a transmission layer (not shown), an absorbent layer <NUM> over the transmission layer, a moisture vapor permeable film or cover layer <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 one or more transmission layers assist 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. 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. The wound dressing layers of the electronics area and the absorbent layer can be covered by one continuous cover layer <NUM>. 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.

<FIG> illustrates an embodiment of layers of a wound dressing with the pump and electronic components offset from the absorbent area of the dressing. As illustrated in <FIG>, the dressing can include a wound contact layer <NUM> for placing in contact with the wound. Lower spacer or transmission layers <NUM> and <NUM>' are provided above the wound contact layer <NUM>. In some embodiments, the transmission layer <NUM> can be a separate layer from spacer layer <NUM>' as shown in <FIG>. The lower transmission layers <NUM> and/or <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 transmission layer <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 cutouts or recesses <NUM> can be sized and shaped to embed a pump <NUM>, power source <NUM>, and/or other electronic components. In some embodiments, the layer <NUM> can include multiple spacer or transmission layers stacked together. In some embodiments, the layer <NUM> can include multiple spacer or transmission layers pieced together to surround the electronic components <NUM>. An upper transmission layer <NUM> can be provided above the absorbent layer <NUM>, layer <NUM>, and/or electronic components <NUM>.

The wound dressing <NUM>, <NUM> may incorporate or comprise a multi-care WCL as described herein this section or elsewhere in the specification. One of skill in the art will understand that the wound dressing <NUM>, <NUM> may incorporate any of the multi-care WCLs disclosed herein this section or elsewhere in the specification. In some embodiments, the multi-care WCL layer may be provided below the transmission layer <NUM>. In some embodiments, the multi-care WCL layer may be provided below the wound contact layer <NUM>. In some embodiments, the multi-care WCL layer may replace the transmission layer <NUM>, <NUM>' such that the multi-care WCL layer is provided between an absorbent layer <NUM> and the wound contact layer <NUM>. In some embodiments, the multi-care WCL layer can supplement or replace the absorbent layer <NUM>, <NUM>. In some embodiments, the multi-care WCL layer may be the lowermost layer of the wound dressing. The multi-care WCL layer may have same or substantially similar size and shape with the transmission layers and/or the absorbent layers described herein this section or elsewhere in the specification.

The multi-care WCL layer may be constructed to be flexible but stiff enough to withstand negative pressure, such that the multi-care WCL layer is not collapsed excessively and thereby transmits negative pressure sufficiently to the wound when negative pressure is supplied to the wound dressing <NUM>. The multi-care WCL layer may be constructed to include sufficient number or size of pores to enable transmission of negative pressure through it. Further, the multi-care WCL layer may have suitable thickness to transmit enough negative pressure to the wound. For example, the multi-care WCL layer may have a thickness of <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. In some embodiments, the multi-care WCL layer may have a thickness of approximately <NUM>.

A cover layer or backing layer <NUM> can be positioned over the upper transmission layer <NUM>. The backing layer <NUM> can form a seal to the wound contact layer <NUM> at a perimeter region enclosing the transmission 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>.

In some instances, components of a reduced pressure wound treatment (NPWT) or TNP system/apparatus, such as a wound dressing or a suction adapter may need to be replaced during treatment. For example, the wound dressing may be saturated with wound exudate, or a suction adapter may be clogged or damaged. Or, different types of TNP systems may need to be used at different stages of the treatment. For example, a wound may initially contain and generate larger amounts of exudate, and the treatment may start with a system including a larger pump and a canister for the collection of greater volumes of wound exudate, such as RENASYS-F, RENASYS-G, RENASYS AB sold by Smith & Nephew. As the healing progresses and less exudate is produced, the patient may be switched to a smaller disposable/portable device such as PICO sold by Smith & Nephew. Such a change in pump and dressing arrangement may improve the experience for the patient, allowing the patient to avoid an unneeded bulkier dressing and canister combination.

Wound dressing or drapes covering the wound may need to be removed in these instances when switching pump types, thereby exposing the wound for a certain time. For example, different types of TNP systems may use different wound dressings or drapes, or wound dressings or drapes may be damaged when the rest of the TNP system is decoupled from the wound dressings or drapes. Further, the wound may be exposed to infection while uncovered.

To keep the wound covered and thereby reduce the risk of infection, a drape or wound dressing will need to be resilient enough to withstand multiple removal and installation steps of TNP systems while maintaining a seal over/around a wound. Further, a drape or a wound dressing which can accommodate different types of TNP systems without being removed from the wound may be needed.

<FIG> illustrates an exploded view of a drape <NUM> for negative pressure wound therapy (NPWT). In the illustrated embodiment, according to the invention, the drape or cover layer <NUM> includes a wound contact layer <NUM>, a spacer layer <NUM>, a support layer <NUM>, a cover layer <NUM> and a reinforcement member <NUM>. The drape <NUM> may include any additional components of wound dressings or drapes described elsewhere herein the specification.

In some embodiments, the wound contact layer <NUM> is the lowermost layer of the drape <NUM> and may act as the primary interface between a wound and the drape <NUM>. The wound contact layer <NUM> may be similar to any wound contact layers described elsewhere herein, such as the wound contact layer <NUM> and the wound contact layer <NUM>. For example, the wound contact layer <NUM> may 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 perforations preferably comprise through holes in the wound contact layer <NUM> which enable fluid to flow through the wound contact layer <NUM>. The wound contact layer <NUM> may help preventing 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 drape <NUM> while also creating an air tight seal around the wound in order to maintain negative pressure at the wound. In operation, the wound contact layer <NUM> may 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 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. 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 drape <NUM> whilst an upper pressure sensitive adhesive layer may be provided on the upper surface of the wound contact layer <NUM>. The pressure sensitive adhesive, which may be a silicone, hot melt, hydrocolloid or acrylic based adhesive or other such adhesive, may be formed on both sides or optionally on a selected one or none of the sides of the wound contact layer <NUM>. When a lower pressure sensitive adhesive layer is utilized may be helpful to adhere the drape <NUM> to the skin around a wound site. In some embodiments, the wound contact layer <NUM> 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.

The spacer layer <NUM> is positioned above the wound contact layer <NUM>. The spacer layer <NUM> can assist in distributing negative pressure evenly to the wound surface and/or wicking exudate away from the wound and/or periwound into upper layers of the drape <NUM>. The spacer layer <NUM> may be similar with any spacer layer or transmission layer described elsewhere herein, such as the transmission layer <NUM>. For example, the spacer layer <NUM> can be a porous material. The spacer 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 spacer layer <NUM> may remain open under the typical pressures that will be applied during negative pressure wound therapy as described above, such that the whole wound site sees an equalized negative pressure. The spacer 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 three-dimensional material can comprise a 3D spacer fabric material similar to the material described in International Publication <CIT> and International Publication <CIT>.

The cover layer <NUM> may be similar to any cover layers or backing layers described elsewhere herein, such as the cover layer <NUM>, the cover layer or backing layer <NUM> and the backing layer <NUM>. For example, in some embodiments, 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 can be made between the cover layer <NUM> and a wound site where a negative pressure can be established. 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> may be sealed to the wound contact layer <NUM> in a border region around the circumference of the drape, ensuring that no air is drawn in through the border area, for example via adhesive or welding techniques. The cover layer <NUM> can protect the wound from external bacterial contamination (bacterial barrier) and/or allow liquid from wound exudates to be transferred through the layer and evaporated from the film outer surface. The cover layer <NUM> may comprise two layers; a polyurethane film and an adhesive pattern spread onto the film. The polyurethane film may be 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 cover layer may be up to about ten times more than the moisture vapor permeability of the dry cover layer. In some embodiments, the cover layer <NUM> is transparent or translucent.

The cover layer <NUM> includes an opening <NUM> through the thickness of the cover layer <NUM>. The opening <NUM> is fluidically connected with a source of a negative pressure, and deliver negative pressure to the drape <NUM> and the wound, and wound exudate may be moved from the drape <NUM> through the opening <NUM>. In some embodiments, the opening <NUM> may include one or more openings. In the illustrated embodiment, the opening <NUM> is formed in a central region of the cover layer <NUM>, but the opening <NUM> may be positioned at any suitable location in the cover layer <NUM>. For example, the opening <NUM> may be horizontally biased to one side. In the illustrated embodiment, the opening <NUM> has a square or a substantially square shape, but the opening <NUM> may have any suitable shapes. For example, the opening <NUM> can have a circular, rectangular, triangular, or oval shape.

In some embodiments, the drape <NUM> can include layers or components to enhance structural integrity of the drape <NUM>, such that the drape <NUM> can withstand multiple application and removal of TNP components (e.g. a wound dressing, a suction adapter) to the it. The drape <NUM> includes the support layer <NUM>. The support layer <NUM> may be more rigid than other layers such as the cover layer <NUM>, the spacer layer <NUM> or the wound contact layer <NUM>, such that the support layer <NUM> can increase the overall structural strength of the drape <NUM>. However, the support layer <NUM> may be elastic and can be bent to some degree, such that the drape <NUM> does not disrupt the wound tissue and conforms to the patient's body. The support layer <NUM> may have a thickness less than about: <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. The support layer <NUM> may include one or more polymeric materials, such as polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), or silicone. In some embodiments, the support layer <NUM> is completely or substantially transparent. In some embodiments, the support layer <NUM> is translucent. The support layer <NUM> includes one or more perforations <NUM> through the support layer to facilitate wound exudate removal. Each of the one or more perforations <NUM> may be sized to allow wound exudate flow through it. For example, each of the perforations <NUM> may have a diameter greater than about: <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. In some embodiments, the one or more perforations <NUM> may be distributed across the support layer <NUM>. In some embodiments, the one or more perforations <NUM> may be more concentrated at one or more locations, such as a central region, or a region beneath the opening <NUM>.

As illustrated in <FIG>, the support layer <NUM> is included between the cover layer <NUM> and the spacer layer <NUM>. The support layer <NUM> may be positioned anywhere between the cover layer <NUM> and the wound contact layer <NUM>. In some embodiments, the support layer <NUM> may be included between the spacer layer <NUM> and the wound contact layer <NUM>. In some embodiments, the support layer <NUM> can be positioned immediately below the cover layer <NUM>. The support layer <NUM> may be at least partially attached to the wound side surface of the cover layer <NUM> using adhesive, heat sealing, or any other suitable methods, such that the support layer <NUM> provides resilience to the cover layer <NUM>. In some embodiments, the opening <NUM> expose a portion of the support layer <NUM> underneath the opening <NUM>. In some embodiments, when a suction adapter is applied to the drape <NUM> over the opening <NUM> of the cover layer <NUM>, at least a portion of the suction adapter can be coupled to the exposed portion of the support layer <NUM>, such that the force exerted by the suction adapter to the cover layer <NUM> can be reduced. In some embodiments, the support layer <NUM> may be smaller than the spacer layer <NUM>. In some embodiments, the drape <NUM> may further include a removable or replaceable cover for the opening <NUM>, such that the opening <NUM> may be sealed when no suction adapter or the wound dressing is attached to the drape <NUM>.

The reinforcement member <NUM> is positioned over the cover layer <NUM>. The reinforcement member <NUM> can reinforce the cover layer <NUM> over the area where a wound dressing or a suction adapter of a TNP system will be applied. In some embodiments, the reinforcement member <NUM> may be made of similar material with the cover layer <NUM>. For example, the reinforcement member <NUM> may be made of a polymeric film material. In some embodiments, the reinforcement member <NUM> may be made of a stiffer plastic material. The reinforcement member <NUM> may be made of a material more stiff or resilient than the cover layer <NUM>. For example, the reinforcement member may be made of a polyurethane, polyprolylene, polyethylene, polyvinylchloride, silicone or a combination thereof. The lower surface of the reinforcement member <NUM> at the wound-facing side may have an adhesive, such that the reinforcement member <NUM> can be attached to the upper surface of the cover layer <NUM>.

As illustrated in <FIG>, the reinforcement member <NUM> may have a substantially rectangular shape, and a rectangular-shaped wound dressing with a similar horizontal dimension with the reinforcement member <NUM> may be applied over the reinforcement member <NUM>, forming an airtight seal. The reinforcement member <NUM> may have any suitable shape, such that it can accommodate a similarly shaped wound dressing or an applicator of a suction adapter. In some embodiments, the reinforcement member <NUM> may be made of an opaque material, such that the reinforcement member <NUM> is visible from above, and serve as a guide for application of a wound dressing or a suction adapter over the drape <NUM>. In some embodiments, the reinforcement member <NUM> may be colored for enhanced visibility.

As illustrated in <FIG>, the reinforcement member <NUM> may include a window <NUM>, such that the opening <NUM> of the cover layer <NUM> can be exposed for the connection with a TNP system. Further, if a size of the window <NUM> is greater, a larger portion of the cover layer <NUM> is exposed, thus allowing faster moisture removal from the drape <NUM> through the moister vapor permeable cover layer <NUM>. However, in some embodiments, maintaining the size of the window <NUM> lower than a certain amount will keep the reinforcement layer <NUM> resilient enough, positively affecting the reinforcing role of the reinforcement member. For example, the window <NUM> may have an area smaller than <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% of the total area covered by the reinforcement member <NUM> including the window <NUM>. In some embodiments, the window <NUM> may have a same or substantially same shape with the reinforcement member <NUM>, such that the window <NUM> defines an inner perimeter of the reinforcement member <NUM> which extends at least substantially along an outer perimeter of the reinforcement member <NUM>.

As discussed elsewhere herein, the drape <NUM> may be used with components of different TNP systems or apparatus. <FIG> illustrate the drape <NUM> in use with a negative pressure wound therapy apparatus including a suction adapter <NUM>, for example a RENASYS soft port by Smith & Nephew, and <FIG> illustrate an illustrates the drape <NUM> in use with a negative pressure wound therapy apparatus including a wound dressing <NUM>, for example, a PICO wound dressing by Smith & Nephew. One of skill in the art will understand and as explained further below, that the drape <NUM> may be used with both a suction adapter <NUM> and a wound dressing <NUM>, and a suction adapter and wound dressing may be switched, depending on the course of treatment.

As shown in <FIG>, the suction adapter <NUM> may be coupled to the drape <NUM>. In some embodiments, the suction adapter <NUM> may be similar with the suction adapter <NUM> described in relation to <FIG>, and the description about the suction adapter <NUM> and its parts may apply to the suction adapter <NUM> except as noted below. Further, the suction adapter <NUM> may be fluidically connected to a source of negative pressure such as the pump <NUM> described in relation to <FIG> or the pump assembly <NUM> and the canister <NUM> described in relation to <FIG>, and deliver negative pressure to the drape <NUM> and the wound under the drape <NUM>.

In some embodiments, the drape <NUM> may be placed over a suitably-prepared wound, which may in some cases be filled with a wound packing material such as foam or gauze. The drape <NUM> may be attached to healthy skin around the wound, for example using an adhesive applied at the lower surface of the wound contact layer <NUM>, and form a fluid tight seal around the wound. In some embodiments, an additional cover or backing layer may be applied to cover the opening <NUM> for prevention of contamination of the wound.

After the drape <NUM> is secured over the wound, the opening <NUM> may be exposed, and a distal end of the suction adapter <NUM> may be applied over the opening <NUM> as shown in <FIG>. While not shown in <FIG>, a proximal end of the suction adapter <NUM> may be fluidically connected to a source of negative pressure, such as the pump <NUM> described in relation to <FIG> or the pump assembly <NUM> and the canister <NUM> described in relation to <FIG>. In some embodiments, the suction adapter <NUM> may be coupled to the drape <NUM> before placing the drape <NUM> over the wound.

The suction adapter <NUM> may include an applicator <NUM> at the distal end to facilitate coupling of the suction adapter <NUM> to the drape <NUM>. The applicator <NUM> may be similar with the applicator <NUM>, and include an adhesive under the wound facing surface of the applicator <NUM>. In some embodiments, the applicator <NUM> may be attached to the support layer <NUM> using the adhesive. The outer edge of the applicator <NUM> may be attached to the cover layer <NUM> around the opening <NUM>, such that a fluid tight seal between the suction adapter <NUM> and the drape <NUM> can be formed. In some embodiments, the applicator <NUM> may have greater dimension than the opening <NUM>, such that the outer edge of the applicator <NUM> extends over the cover layer <NUM>. The applicator <NUM> may be transparent or translucent to facilitate positioning the distal end of the suction adaptor <NUM> over the opening <NUM>. When the negative pressure is provided by the source of negative pressure, wound exudate may be removed from the wound through the perforations <NUM> of the support layer <NUM> toward the suction adaptor <NUM>.

The suction adapter <NUM> may be decoupled from the drape <NUM> without removing the drape <NUM> from the wound or substantially damaging the drape <NUM>, such that the drape <NUM> can be further used.

As shown in <FIG>, the wound dressing <NUM> may be coupled to the drape <NUM>. In some embodiments, the wound dressing <NUM> may be coupled to the drape <NUM> after the suction adapter <NUM> is decoupled from the drape <NUM>. Conversely, a suction adapter <NUM> may be coupled to the drape <NUM> after the wound dressing <NUM> is decoupled from the drape <NUM>. The drape <NUM> may stay attached over the wound during the transition. In some embodiments, the wound dressing <NUM> may be similar with the wound dressing <NUM> described in relation to <FIG>, and the description about the wound dressing <NUM> and its parts may apply to the wound dressing <NUM> except as noted below. Further, the wound dressing <NUM> may be fluidically connected to a source of negative pressure such as the pump <NUM> described in relation to <FIG>, and deliver negative pressure to the drape <NUM> and the wound under the drape <NUM>. In some embodiments, the wound dressing <NUM> may be similar with the wound dressing <NUM> described in relation to <FIG>, and may include a source of negative pressure.

The wound dressing <NUM> may be applied over the opening <NUM> as shown in <FIG>. While not shown in <FIG>, the wound dressing <NUM> may be fluidically connected to a source of negative pressure. In some embodiments, the wound dressing <NUM> may be coupled to the drape <NUM> before placing the drape <NUM> over the wound. In some embodiments, the wound dressing <NUM> may be coupled to the drape <NUM>, after another wound dressing or suction adapter has been coupled and decoupled to the drape <NUM>. For example, after the drape <NUM> is applied to the wound, the suction adapter <NUM> may be coupled to the drape <NUM>, decoupled from the drape <NUM> after a certain amount of time of treatment, and the wound dressing <NUM> may be coupled to the drape <NUM>.

The wound dressing <NUM> may include an adhesive at its lower surface at wound facing side for coupling of the suction adapter <NUM> to the drape <NUM>. In some embodiments, the wound dressing <NUM> may be attached to the reinforcement member <NUM> using the adhesive. When coupled to the drape <NUM>, the wound dressing <NUM> may partially or entirely cover the reinforcement member <NUM>. In some embodiments, the wound dressing <NUM> may be further attached to the cover layer <NUM> under the window <NUM>, and/or the support layer <NUM> using the adhesive. In some embodiments, the wound dressing <NUM> may be attached only to the reinforcement member <NUM>, such that it can be removed without damaging the cover layer <NUM>. In some embodiments, the wound dressing <NUM> may be removed and replaced with another wound dressing multiple times as the treatment continues. During this process, the drape <NUM> may stay attached over the wound.

Aspects of the disclosure can be modified, if necessary, to employ the systems, functions, and concepts of the various references described herein to provide yet further implementations.

Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of protection. Indeed, the novel systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the systems described herein may be made. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated or disclosed may differ from those shown in the figures. For example, the actual steps or order of steps taken in the disclosed processes may differ from those shown in the figure. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the claims.

Although the present disclosure includes certain embodiments, examples and applications, it will be understood by those skilled in the art that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments or uses and obvious modifications thereof, including embodiments which do not provide all of the features and advantages set forth herein. Accordingly, the scope of the present disclosure is not intended to be limited by the described embodiments, and is defined by claims.

Likewise the term "and/or" in reference to a list of two or more items, covers all of the following interpretations of the word: any one of the items in the list, all of the items in the list, and any combination of the items in the list. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application.

Any of the embodiments described herein can be used with a canister or without a canister. Any of the dressing embodiments described herein can absorb and store wound exudate.

The scope of the present disclosure is not intended to be limited by the description of certain embodiments and is defined by the claims. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive.

Claim 1:
A system for negative pressure wound therapy, the system comprising:
a drape comprising:
a cover layer having an opening for fluidically connecting to a source of negative pressure;
a support layer beneath the cover layer having one or more perforations and wherein the drape further comprises a reinforcement member positioned above the cover layer;
a spacer layer for distributing negative pressure beneath the cover layer; and
a wound contact layer beneath the support layer and the spacer layer.