Patent Application
20250090382
Embodiments described herein relate to apparatuses, systems, and methods for the treatment of wounds, for example using dressings in combination with negative pressure wound therapy.
Prior art dressings for use in negative pressure have included a negative pressure source located in a remote location form the wound dressing. Further, when used, wound exudate may soak into the dressing, and the moisture from the wound has made it difficult to incorporate electronic components into the dressing.
The treatment of open or chronic wounds that are too large to spontaneously close or otherwise fail to heal by means of applying negative pressure to the site of the wound is well known in the art. Negative pressure wound therapy (NPWT) systems currently known in the art commonly involve placing a cover that is impermeable or semi-permeable to fluids over the wound, using various means to seal the cover to the tissue of the patient surrounding the wound, and connecting a source of negative pressure (such as a vacuum pump) to the cover in a manner so that negative pressure is created and maintained under the cover. It is believed that such negative pressures promote wound healing by facilitating the formation of granulation tissue at the wound site and assisting the body's normal inflammatory process while simultaneously removing excess fluid, which may contain adverse cytokines and/or bacteria. However, further improvements in NPWT are needed to fully realize the benefits of treatment.
Many different types of wound dressings are known for aiding in NPWT systems. These different types of wound dressings include many different types of materials and layers, for example, gauze, pads, foam pads or multi-layer wound dressings. One example of a multi-layer wound dressing is the PICO dressing, available from Smith & Nephew, which includes a superabsorbent layer beneath a backing layer to provide a canister-less system for treating a wound with NPWT. The wound dressing may be sealed to a suction port providing connection to a length of tubing, which may be used to pump fluid out of the dressing and/or to transmit negative pressure from a pump to the wound dressing.
Prior art dressings for use in negative pressure such as those described above have included a negative pressure source located in a remote location from the wound dressing. Negative pressure sources located remote from the wound dressing have to be held by or attached to the user or other pump support mechanism. Additionally, a tubing or connector is required to connect the remote negative pressure source to the wound dressing. The remote pump and tubing can be cumbersome and difficult to hide in or attach to patient clothing. Depending on the location of the wound dressing, it can be difficult to comfortably and conveniently position the remote pump and tubing. When used, wound exudate may soak into the dressing, and the moisture from the wound has made it difficult to incorporate electronic components into the dressing.
Embodiments of the present disclosure relate to apparatuses and methods for wound treatment. Some of the wound treatment apparatuses described herein comprise a negative pressure source or a pump system for providing negative pressure to a wound. Wound treatment apparatuses may also comprise wound dressings that may be used in combination with the negative pressure sources and pump assemblies described herein. In some embodiments, a negative pressure source is incorporated into a wound dressing apparatus so that the wound dressing and the negative pressure source are part of an integral or integrated wound dressing structure that applies the wound dressing and the negative pressure source simultaneously to a patient's wound. The negative pressure source and/or electronic components may be positioned between a wound contact layer and a cover layer of the wound dressing. The negative pressure source and/or electronic components may be separated and/or partitioned from an absorbent area of the dressing. A switch may be integrated with the wound dressing to control operation of the wound dressing apparatus. A connector may be direct air from an outlet of the negative pressure source to the environment. A non-return valve may inhibit back flow of air into the wound dressing. These and other embodiments as described herein are directed to overcoming particular challenges involved with incorporating a negative pressure source and/or electronic components into a wound dressing.
In some aspects, a wound dressing apparatus comprises a wound contact layer configured to be positioned in contact with a wound, a first area over the wound contact layer comprises a lower spacer layer and an absorbent layer, a second area over the wound contact layer comprising a plurality of spacer layers and a negative pressure source and/or electronic components positioned within or between the plurality of spacer layers, wherein the first area is positioned adjacent to the second area and separated by a partition, an upper spacer layer configured to cover the first area and the second area and to allow air to be communicated between the first area and second area around the partition, and a cover layer configured to cover and form a seal over the wound contact layer, the upper spacer layer, the first area, and the second area.
The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. The plurality of spacer layers in the second area can include a third spacer layer beneath the negative pressure source and/or electronic components and a fourth spacer layer positioned above the negative pressure source and/or electronic components, wherein the fourth spacer layer comprises one or more cutouts or recesses configured to receive the negative pressure source and/or electronic components. The partition can include a non-porous dam. The apparatus can comprise one or more user interface components configured to allow a user to operate the negative pressure source and/or electronic components.
In some aspects, a wound dressing apparatus can comprise a wound dressing configured to be positioned over a wound site, a negative pressure source disposed on or positioned within the wound dressing, and a switch integrated with the wound dressing configured to control operation of the wound dressing apparatus.
The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. The switch can be at least one of positioned within, disposed on, or embedded in the wound dressing. The wound dressing can comprise a wound dressing body and a wound dressing border, the wound dressing border extending along at least of a portion of a perimeter defined around the wound dressing body. The switch can be integrated with the wound dressing body or the wound dressing border. The switch can be at least one of positioned within, disposed on, or embedded in the wound dressing body or the wound dressing border. The wound dressing body and the wound dressing border can comprise a top layer and a bottom layer, the top layer comprising a cover layer and the bottom layer comprising a wound contact layer, the switch being integrated with the wound dressing proximally adjacent at least one of the top layer and the bottom layer. The wound dressing body or the wound dressing border can comprise a flexiboard layer beneath the switch to dissipate and/or inhibit the transfer of a compression force to the wound site when the switch is actuated. The switch can be configured to be actuated by pressing the switch in a first direction with a finger. The wound dressing can comprise a tab that extends from the wound dressing border, the switch being integrated with the tab. The switch can be at least one of positioned within, disposed on, or embedded in the tab. The tab can be configured to be lifted by a user so that the switch can be actuated by the user by applying force to the switch in two opposing directions on opposite or different sides of the tab. The wound dressing can comprise a joint between the tab and the wound dressing border to facilitate movement of the tab without applying force to the wound dressing body or the wound dressing border, the tab being configured to rotate about the joint when a user moves the tab. The apparatus can include one or more indicators configured to indicate one or more statuses of the wound dressing apparatus. The one or more indicators can comprise one or more visual indicators. The one or more visual indicators can comprise one or more light emitting diodes (LEDs). The one or more indicators can be configured to indicate a battery level of the wound dressing apparatus. The one or more indicators can extend around the switch. The one or more indicators can circumferentially extend around the switch. The switch can be positioned in a sub-flush position relative to the one or more indicators to inhibit accidental or inadvertent actuation of the switch. The switch can be selectively operable by a user to control operation of the negative pressure source. The switch can be selectively operable by a user to turn on and turn off the negative pressure source. The switch can be electrically connected to the negative pressure source. The negative pressure source can be a micro pump.
In some aspects, a wound dressing apparatus can comprise a wound dressing configured to be positioned over a wound site, a negative pressure source disposed on or positioned within the wound dressing, the negative pressure source comprising an inlet and an outlet, the negative pressure source being configured to apply negative pressure to the wound site via the inlet and being further configured to remove air from the wound dressing via the outlet, and a connector comprising first and second ends and a flow path therebetween, wherein the first end is in fluid communication with the outlet and the second end is open to an environment outside the wound dressing, wherein a portion of the flow path extends through an opening defined in the wound dressing, the flow path being configured to direct air from the outlet to the environment.
The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. The opening in the wound dressing can be defined on a top layer of the wound dressing. The top layer can comprise a moisture vapor permeable film. The opening in the wound dressing can be defined between a top layer and a bottom layer of the wound dressing. The opening in the wound dressing can be defined through an edge of the wound dressing between a top layer and a bottom layer of the wound dressing. The top layer can comprise a moisture vapor permeable film and the bottom layer comprises a wound contact layer. The connector can comprise a spacer that extends between a first and second portion of the connector, the spacer being configured to resist collapse of the connector when the connector is compressed. The first and second portions of the connector can comprise the first and second ends of the connector. The spacer can be enveloped in a film to form a gas tight seal with the wound dressing. The spacer can comprise a length of 3D fabric material. The film can be a plastic film. The film can be Versapore film having a pore size diameter of about 2 μm. The connector can form a gas tight seal with the wound dressing. The connector can form a gas tight seal with the outlet of the negative pressure source. The connector can be configured to resist collapse, thereby inhibiting occlusion of the connector when the wound dressing is subjected to compressive forces. The connector can be configured to inhibit the ingress of water, foreign bodies, dirt, or bacteria through the opening in the wound dressing. The wound dressing apparatus further can comprise a tube interposed between the outlet and the connector, the tube being coupled to the outlet and the connector. The tube can be configured to extend the connector such that the connector is positioned outside of the wound dressing after the tube passes through the opening in the wound dressing.
In some aspects, a wound dressing apparatus can comprise a wound dressing configured to be positioned over a wound site, a negative pressure source disposed on or positioned within the wound dressing, the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and a non-return valve in fluid communication with the outlet, the non-return valve being configured to inhibit back flow of air into the wound dressing.
The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. The non-return valve can be configured to inhibit back flow of air into the wound dressing through the outlet. The non-return valve can be connected to the outlet. The non-return valve can comprise a first end in fluidic communication with the outlet and a second end in fluid communication with an exhaust component, the exhaust component being configured to direct air from the outlet to the environment. The first end of the non-return valve can be connected to the outlet and the second end of the non-return valve is connected to the exhaust component. The non-return valve is at least partially disposed in the outlet. The apparatus can include an exhaust system having first and second ends, wherein the exhaust system is interposed between the outlet and the non-return valve such that the first end is connected to the outlet and the second end is connected to the non-return valve. The apparatus can include an exhaust system, wherein the non-return valve is at least partially integrated with the exhaust system. The non-return valve can be at least partially integrated with the exhaust system at an end of the exhaust system. The non-return valve can be integrated with the wound dressing. The non-return valve can be positioned within and/or embedded in the wound dressing. The non-return valve can comprise a size configured to fit within the wound dressing. The non-return valve can have a height that is less than a thickness of the wound dressing. The non-return valve can have a low cracking pressure and a low resistance to out flow. The non-return valve can have a cracking pressure of less than 500 Pa for a nominal flow rate of about 1 mL/min through the apparatus. The non-return valve can have an out flow resistance of less than 30 mL/min as measured with a nominally fixed vacuum of 10.7 kPa below atmosphere. The non-return valve can provide a resistance to air flowing out of the wound dressing apparatus of less than 100 mL/min as measured with a nominally fixed vacuum of 10.7 kPa below atmosphere. The negative pressure source and the non-return valve together can allow air to leak into the wound dressing apparatus via the outlet at a negligible rate of less than 2.0 mL/min. The non-return valve can be a mechanical valve that is self-activated. The non-return valve can comprise a duckbill valve. The non-return valve can comprise a reed valve. The reed valve can comprise a 75 micron thick polyester reed valve. The non-return valve can comprise a cavity with an inlet port and an outlet port and a reed at least partially disposed in the cavity. The non-return valve can comprise a crescent shape. The crescent shape can be defined by a housing having a first curved surface that intersects a second surface. The second surface can be flat. The second surface can be curved, the second surface can have a radius of curvature that is greater than a radius of curvature of the first curved surface. The second surface can be semi-rigid or flexible such that it is configured to conform to a surface of the wound site. The non-return valve can comprise a crescent shape, wherein the reed can comprise a rectangular shape with circular ends. The non-return valve can comprise a crescent shape, wherein the reed can include a curved portion. The negative pressure source can be a micro pump. The apparatus can include a controller configured to control the operation of the micro pump to apply negative pressure to the wound site.
Embodiments of the present disclosure relate to apparatuses and methods for wound treatment. Some of the wound treatment apparatuses described herein comprise a negative pressure source or a pump system for providing negative pressure to a wound. Wound treatment apparatuses may also comprise wound dressings that may be used in combination with the negative pressure sources and pump assemblies described herein. In some embodiments, a negative pressure source is incorporated into a wound dressing apparatus so that the wound dressing and the negative pressure source are part of an integral or integrated wound dressing structure that applies the wound dressing and the negative pressure source simultaneously to a patient's wound. The negative pressure source and/or electronic components may be positioned between a wound contact layer and a cover layer of the wound dressing. A component may be used to prevent wound exudate from contacting the inlet of the negative pressure source. These and other embodiments as described herein are directed to overcoming particular challenges involved with incorporating a negative pressure source and/or electronic components into a wound dressing.
In some aspects, a wound dressing apparatus comprises a wound dressing configured to be positioned over a wound site, the wound dressing comprising a wound contact layer configured to be positioned in contact with a wound, a first area and a second area positioned adjacent to the first area, wherein the first area comprises an absorbent material and the second area is configured to receive a negative pressure source, and a cover layer configured to cover and form a seal over the wound contact layer, the first area, and the second area, a negative pressure source disposed on or positioned within the second area of the wound dressing, the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and a component in fluid communication with the inlet, the component defining a plurality of flow paths between an interior of the wound dressing and the inlet such that occlusion of the inlet is inhibited, and wherein the component is in fluid communication with the absorbent material and configured to inhibit flow of wound exudate from the wound site into the inlet.
The apparatus of the preceding paragraph may also include any combination of the following features described in this paragraph, among others described herein. Each of the features described in the following paragraphs may also be part of another embodiment that does not necessarily include all of the features of the previous paragraph. The component can comprise a hydrophobic material configured to repel wound exudate. The component can comprise a material having a pore size configured to resist ingress of wound exudate due to capillary action. The component can comprise one or more porous polymer molded components. The polymer comprising the one or more porous polymer molded components can be hydrophobic and can have a pore size in the range of approximately 20 microns to approximately 40 microns. The pore size can be approximately 30 microns. The polymer comprising the one or more porous polymer molded components can be hydrophobic and can have a pore size in the range of approximately 5 microns to approximately 40 microns. The pore size can be approximately 10 microns.
The polymer can be POREX® or PORVAIR®. The polymer can be one of hydrophobic polyethylene or hydrophobic polypropylene. Each of the one or more porous polymer molded components can be configured to increase the contact area between the pump inlet and the interior of the wound dressing. The one or more porous polymer components have a three-dimensional shape. For example, the one or more porous polymer components can be crescent-shaped, thimble-shaped, or cuboid or generally cuboid shaped. The one or more porous polymer components can also have curved or beveled corners and/or edges. The one or more porous polymer components can be configured to attach to at least one of the inlet and an end of a tubular extension in fluid communication with the inlet and the interior of the wound dressing.
The component can comprise one or more micro porous membranes attached to the inlet. The wound dressing apparatus can comprise a spacer material disposed within the membrane, the spacer material configured to inhibit the membrane from collapsing. The micro porous membrane can comprise Versapore having a 0.2 micron pore size (Pall). The component can comprise one or more lengths of fine bore tubing defining a plurality of holes along their lengths. The one or more lengths of fine bore tubing can form one or more loops between the inlet and the wound dressing. The one or more lengths of fine bore tubing can extend from the inlet to one or more different points in the wound dressing. The negative pressure source can be a micro pump. The wound dressing apparatus can comprise a controller configured to control the operation of the micro pump to apply negative pressure to the wound site. The absorbent material can be configured to absorb wound exudate. The component can be attached to the inlet. The component can be fitted to the inlet.
In one embodiment, a wound dressing apparatus comprises a wound dressing configured to be positioned over a wound site, a negative pressure source disposed on or positioned within the wound dressing, the negative pressure source comprising an inlet and an outlet and being operable to apply negative pressure to the wound site, and a porous polymer component fitted to the inlet of the negative pressure source and in fluid communication with the inlet, the porous polymer component comprising a three-dimensional body defining a plurality of flow paths between an interior of the wound dressing and the inlet such that occlusion of the inlet is inhibited.
The porous polymer component can comprise a hydrophobic material configured to repel wound exudate. The porous polymer component can have a pore size in the range of approximately 20 microns to approximately 40 microns. The pore size can be approximately 30 microns. The porous polymer component can have a pore size in the range of approximately 5 microns to approximately 40 microns. The pore size can be approximately 10 microns. The polymer can be PORVAIR Vyon®. The porous polymer component can be crescent-shaped, thimble-shaped, or cuboid or generally cuboid shaped. The porous polymer component can also have curved or beveled corners and/or edges.
Any of the features, components, or details of any of the arrangements or embodiments disclosed in this application, including without limitation any of the pump embodiments and any of the negative pressure wound therapy embodiments disclosed below, are interchangeably combinable with any other features, components, or details of any of the arrangements or embodiments disclosed herein to form new arrangements and embodiments.
Embodiments of the present disclosure will now be described hereinafter, by way of example only, with reference to the accompanying drawings in which:
Embodiments disclosed herein relate to apparatuses and methods of treating a wound with reduced pressure, including a source of negative pressure and wound dressing components and apparatuses. The apparatuses and components comprising the wound overlay and packing materials, if any, are sometimes collectively referred to herein as dressings.
It will be appreciated that throughout this specification reference is made to a wound. It is to be understood that the term wound is to be broadly construed and encompasses open and closed wounds in which skin is torn, cut or punctured or where trauma causes a contusion, or any other superficial or other conditions or imperfections on the skin of a patient or otherwise that benefit from reduced pressure treatment. A wound is thus broadly defined as any damaged region of tissue where fluid may or may not be produced. Examples of such wounds include, but are not limited to, abdominal wounds or other large or incisional wounds, either as a result of surgery, trauma, sterniotomies, fasciotomies, or other conditions, dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, bums, diabetic ulcers, pressure ulcers, stoma, surgical wounds, trauma and venous ulcers or the like.
It will be understood that embodiments of the present disclosure are generally applicable to use in topical negative pressure (“TNP”) therapy systems. Briefly, negative pressure wound therapy assists in the closure and healing of many forms of “hard to heal” wounds by reducing tissue oedema; encouraging blood flow and granular tissue formation; removing excess exudate and may reduce bacterial load (and thus infection risk). In addition, the therapy allows for less disturbance of a wound leading to more rapid healing. TNP therapy systems may also assist on the healing of surgically closed wounds by removing fluid and by helping to stabilize the tissue in the apposed position of closure. A further beneficial use of TNP therapy can be found in grafts and flaps where removal of excess fluid is important and close proximity of the graft to tissue is required in order to ensure tissue viability.
As is used herein, reduced or negative pressure levels, such as −X mmHg, represent pressure levels relative to normal ambient atmospheric pressure, which can correspond to 760 mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure value of −X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or, in other words, an absolute pressure of (760−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., −40 mmHg is less than −60 mmHg). Negative pressure that is “more” or “greater” than −X mmHg corresponds to pressure that is further from atmospheric pressure (e.g., −80 mmHg is more than −60 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, 760 mmHg.
The negative pressure range for some embodiments of the present disclosure can be approximately −80 mmHg, or between about −20 mmHg and −200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, which can be 760 mmHg. Thus, −200 mmHg would be about 560 mmHg in practical terms. In some embodiments, the pressure range can be between about −40 mmHg and −150 mmHg. Alternatively, a pressure range of up to −75 mmHg, up to −80 mmHg or over −80 mmHg can be used. Also in other embodiments a pressure range of below −75 mmHg can be used. Alternatively, a pressure range of over approximately −100 mmHg, or even −150 mmHg, can be supplied by the negative pressure apparatus.
In some embodiments of wound closure devices described herein, increased wound contraction can lead to increased tissue expansion in the surrounding wound tissue. This effect may be increased by varying the force applied to the tissue, for example by varying the negative pressure applied to the wound over time, possibly in conjunction with increased tensile forces applied to the wound via embodiments of the wound closure devices. In some embodiments, negative pressure may be varied over time for example using a sinusoidal wave, square wave, and/or in synchronization with one or more patient physiological indices (e.g., heartbeat). Examples of such applications where additional disclosure relating to the preceding may be found include U.S. Pat. No. 8,235,955, titled “Wound treatment apparatus and method,” issued on Aug. 7, 2012; and U.S. Pat. No. 7,753,894, titled “Wound cleansing apparatus with stress,” issued Jul. 13, 2010. The disclosures of both of these patents are hereby incorporated by reference in their entirety.
International Application PCT/GB2012/000587, titled “WOUND DRESSING AND METHOD OF TREATMENT” and filed on Jul. 12, 2012, and published as WO 2013/007973 A2 on Jan. 17, 2013, is an application, hereby incorporated and considered to be part of this specification, that is directed to embodiments, methods of manufacture, and wound dressing components and wound treatment apparatuses that may be used in combination or in addition to the embodiments described herein. Additionally, embodiments of the wound dressings, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in U.S. Provisional Application No. 61/650,904, filed May 23, 2012, titled “APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,” International Application No. PCT/IB2013/001469, filed May 22, 2013, titled “APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,” and published as WO 2013/175306 on Nov. 28, 2013, U.S. patent application Ser. No. 14/418,874, filed Jan. 30, 2015, published as U.S. Publication No. 2015/0216733, published Aug. 6, 2015, titled “WOUND DRESSING AND METHOD OF TREATMENT,” U.S. patent application Ser. No. 14/418,908, filed Jan. 30, 2015, published as U.S. Publication No. 2015/0190286, published Jul. 9, 2015, titled “WOUND DRESSING AND METHOD OF TREATMENT,” U.S. patent application Ser. No. 14/658,068, filed Mar. 13, 2015, U.S. Application No. 2015/0182677, published Jul. 2, 2015, titled “WOUND DRESSING AND METHOD OF TREATMENT,” the disclosures of which are hereby incorporated by reference in their entireties. Embodiments of the wound dressings, wound treatment apparatuses and methods described herein may also be used in combination or in addition to those described in U.S. patent application Ser. No. 13/092,042, filed Apr. 21 2011, published as US2011/0282309, titled “WOUND DRESSING AND METHOD OF USE,” and which is hereby incorporated by reference in its entirety, including further details relating to embodiments of wound dressings, the wound dressing components and principles, and the materials used for the wound dressings. Additionally, the present application is related to U.S. Provisional Application No. 62/304,790, filed Mar. 7, 2016, titled “REDUCED PRESSURE APPARATUSES AND METHODS, the subject matter of which is considered to be part of this application and is included in the Appendix below.
Disclosed embodiments relate to apparatuses and methods for wound treatment. In some embodiments, a negative pressure source is incorporated into a wound dressing apparatus so that the wound dressing and the negative pressure source are part of an integral or integrated wound dressing structure that applies the wound dressing and the negative pressure source simultaneously to a patient's wound. The negative pressure source and/or electronic components may be positioned between a wound contact layer and a cover layer of the wound dressing. The negative pressure source and/or electronic components may be separated and/or partitioned from an absorbent area of the dressing. A switch may be integrated with the wound dressing to control operation of the wound dressing apparatus. A connector may be direct air from an outlet of the negative pressure source to the environment. A non-return valve may inhibit back flow of air into the wound dressing.
In some embodiments, a source of negative pressure (such as a pump) and some or all other components of the TNP system, such as power source(s), sensor(s), connector(s), user interface component(s) (such as button(s), switch(es), speaker(s), screen(s), etc.) and the like, can be integral with the wound dressing. As is illustrated in
In some embodiments, the dressing can include the power source and other components, such as electronics, on and/or incorporated into the dressing and can utilize a wound contact layer and a first spacer layer within the dressing. The wound contact layer can be 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 first spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. Further, an absorbent layer (such as layer 240) for absorbing and retaining exudate aspirated from the wound can be utilized. In some embodiments, the absorbent includes a shaped form of a superabsorber layer with recesses or compartments for the pump, electronics, and accompanying components. These layers can be covered with one layer of a film or cover layer (or a first cover layer). The first cover layer can include a filter set that can be positioned within one of the recesses. The filter can be configured to align with one of the at least one recesses of the absorbent layer, and the filter can include hydrophobic material to protect the pump and/or other components from liquid exudates. The filter can block fluids while permitting gases to pass through. The pump, electronics, switch and battery can be positioned on top of the first cover layer. Another section of spacer, a second spacer, can be positioned above and/or surrounding the pump. In some embodiments, the second spacer can be smaller than the first spacer used above the wound contact layer. A section of top film or cover layer (or a second cover layer) is positioned over the top of the second spacer with a second filter associated with or positioned within the second cover layer. In some embodiments, the first and second cover layer can be made of the same material. In some embodiments, the first and second cover layers can be made of different material.
A second filter can be alternative or additionally used. For example, filter 220 can be constructed from antibacterial and/or antimicrobial materials so that the pump can exhaust gases into the atmosphere. Filter 220 can also help to reduce noise produced by the pump.
In certain embodiments, the first and second cover layers include a moisture vapor permeable material that protects the pump and electronic components from liquid exudate removed from the wound and other liquids, while allowing gases through. The pump and electronics can be pouched between the fluid impermeable membranes or cover layers with the only input and output being a filter on each side of the pump. The membranes and filter can protect the electronics from liquid from both sides. In some embodiments, the dressing and integrated electronics pouch can be used in the shower and/or can be in contact with liquid without impeding the operation of the pump and dressing.
In some embodiments, in addition to or instead of one or more batteries, one or more alternative energy generators (such as RF energy harvester, thermal energy harvester, and the like) can be included into the pump to provide an alternative to traditional power sources. Examples of energy harvesters are described in U.S. Provisional Application No. 62/097,272, filed on Dec. 29, 2014 and U.S. Provisional Application No. 62/172,704, filed on Jun. 8, 2015, and titled “Negative Pressure Wound Therapy Apparatus and Methods for Operating the Apparatus,” the disclosures of which are incorporated by reference in their entireties.
A pump 316, electronics package 315, and power source 314 (such as a battery) can be positioned above the cover layer 313 as shown in
In some embodiments, the operation of the pump can vary depending on the environmental humidity level. It can be advantageous to provide mechanisms to drive moisture out of the dressing or otherwise limit or control the humidity of the dressing. In some embodiments, a chamber generated by the layers above the pump can be used to act as a pressurized sink for gases (such as gases exhausted by the pump), thereby increasing the relative humidity (or RH) and delta RH across the outer membrane, which in turn can increase the rate of evaporation.
In some embodiments, the pump can include a piezoelectric transducer that causes negative pressure to be supplied to the wound. In certain embodiments, a secondary device (such as a secondary piezoelectric device) can be used to generate atomisation of the fluid in the dressing, either accelerating evaporation of the water portion of the wound fluid or firing it through the moisture vapor permeable (MVP) top film where it can then evaporate. This can reduce or eliminate the effect of environmental humidity on the capability of the dressing to evaporate water.
In some embodiments, the electronics and/or associated components can be contained in single or multiple sealed pockets or pouches. The pockets or pouches can include the pump, electronics, and/or power source(s) (such as batteries) with or without a spacer layer padding. The packets may be designed to allow easy separation of the electronics from the dressing for disposal.
In some embodiments, a circumference port can be used to bring fluid to the uppermost spacer layer first before being drawn down into the superabsorbent layer and pump. In some embodiments, a full circumference port or multiple circumferential ports can be used. The circumference ports can be used at the perimeter of the wound dressing. This can make the fluid behaviour independent of the direction the dressing is applied in. Without this feature, the capacity can be lower if the port is positioned at the bottom portion of the applied dressing.
In some embodiments, the whole pump pouch can be generated as a specific layer that can be brought into the factory as a reel and/or folded raw material, allowing the manufacture of a full system using the machinery used to manufacture the layers of a wound dressing. The pump and other components can be placed into their respective compartments in the dressing.
In some embodiments, one or more of the following pump additions can be added to the wound dressing with an integrated pump. The pressure sensor can be added onto a substrate of the pump (for example, ceramic substrate). A pressure fuse can be utilized on the pump substrate to discontinue operation of the pump if the pressure generated exceeds an acceptable threshold. Additionally, the pump can be designed for specific pressures. The pump can be designed to disable provision of negative pressure if fluid enters the pump itself.
Further elements can be incorporated into the device to increase the usability of this device. For example, one or more of speaker(s) and/or vibration indicator(s) can be included. The pump can be operated via a controller. One or more user interface elements for operating the pump can be included.
As shown in
In some embodiments, the pump and/or other electronic components can be configured to be positioned adjacent to or next to the absorbent and/or transmission layers so that the pump and/or other electronic components are still part of a single apparatus to be applied to a patient, but the pump and/or other electronics are positioned away from the wound site.
In some embodiments, the pump and/or other electronic components can be configured to be positioned adjacent to or next to the absorbent and/or transmission layers so that the pump and/or other electronic components are still part of a single apparatus to be applied to a patient with the pump and/or other electronics positioned away from the wound site.
The electronics area 1261 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 1261 can include a button or switch 1211 as shown in
The absorbent area 1260 can include an absorbent material 1212 and can be positioned over the wound site. The electronics area 1261 can be positioned away from the wound site, such as by being located off to the side from the absorbent area 1260. The electronics area 1261 can be positioned adjacent to and in fluid communication with the absorbent area 1260 as shown in
In some embodiments, additional layers of dressing material can be included in the electronics area 1261, the absorbent area 1260, or both areas. In some embodiments, the dressing can comprise one or more spacer layers and/or one or more absorbent layer positioned above the contact layer and below the wound cover layer 1213 of the dressing.
The dressing can comprise a wound contact layer (not shown), a spacer layer (not shown), an absorbent layer 1212, a moisture vapor permeable film or cover layer 1213 positioned above the wound contact layer, spacer layer, absorbent layer, or other layers of the dressing. The wound contact layer can be configured to be in contact with the wound. The wound contact layer can include an adhesive on the patient facing side for securing the dressing to the surrounding skin or on the top side for securing the wound contact layer to a cover layer or other layer of the dressing. In operation, the wound contact layer can be configured to provide unidirectional flow so as to facilitate removal of exudate from the wound while blocking or substantially preventing exudate from returning to the wound. The first spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. In some embodiments, the spacer layer can be formed at least partially from a three dimensional (3D) fabric. Further, an absorbent layer (such as layer 1212) 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 1212. 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 1213. 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 absorbent area 1360 of the dressing can comprise a second spacer layer 1311 or lower spacer layer and an absorbent layer 1322 positioned above the wound contact layer 1310. The second spacer layer 1311 can allow for an open air path over the wound site. The absorbent layer 1322 can comprise a super absorber positioned in the absorbent area 1360 of the dressing. The absorbent layer 1322 can retain wound fluid within thereby preventing fluid passage of wound exudates into the electronics area 1361 of the dressing. The wound fluids can flow through the wound contact layer 1310, to the lower spacer layer 1311, and into the absorbent layer 1322. The wound fluids are then spread throughout the absorbent layer 1322 and retained in the absorbent layer 1322 as shown by the white directional arrows for wound fluids in
The electronics area 1361 of the dressing can comprise a plurality of layers of spacer material 1351. In some embodiments, the electronic components 1350 embedded within the plurality of layers of spacer material 1351. The layers of spacer material can have recesses or cut outs to embed the electronic components within whilst providing structure to prevent collapse. The electronic components 1350 can include a pump, power source, controller, and/or an electronics package, although any suitable electronics component is appreciated. In some embodiments, a barrier and/or partition can be provided between the absorbent area 1360 and the dressing layers surrounding the electronic components in the electronics area 1361. A partition 1362 can optionally be positioned between the absorbent area 1360 and the electronics area 1361. The partition 1362 can separate the absorbent layer 1322 and lower air flow spacer layer 1311 from the electronic housing segment of the dressing in the electronic area. The partition 1362 can prevent wound fluid (e.g., wound exudate) from entering the electronic housing section of the dressing. In some embodiments, the partition can be a non-porous dam or other structure. The non-porous dam 1362 can comprise a cyanoacrylate adhesive bead or a strip of silicone. The air pathway through the dressing is shown in
A pump exhaust 1370 can be provided to exhaust air from the pump to the outside of the dressing. The pump exhaust can be in communication with the electronics area 1361 and the outside of the dressing. In some embodiments, the pump exhaust 1370 can be a flexible fluidic connector that comprises a 3D material that allows for pressure to be applied without collapse of the exhaust port as described in more detail herein. Examples of an application where additional disclosure relating to the 3D material can be found include U.S. Publication No. 2015/0141941, titled “Apparatuses and Methods for Negative Pressure Wound Therapy” published on May 21, 2015. The disclosure of this patent is hereby incorporated by reference in its entirety.
The dressings described in
In some embodiments, the absorbent components and electronics components can be overlapping but offset. For example, a portion of the electronics area can overlap the absorbent area, for example overlapping the superabsorber layer, but the electronics area is not completely over the absorbent area. Therefore, a portion of the electronics area can be offset from the absorbent area and only provided over the cushioning spacer layers.
As shown in
The switch can be electrically connected to one or more of the electrical components 1350 of the wound dressing system 1300. For example, in some embodiments, the switch 1330 can be electrically connected to the pump 1304, a power source, a controller, and/or an electronics package, although any suitable electronic component is appreciated. In some embodiments, the switch can be wired and/or be in wireless communication with one or more of the electrical components 1350. The switch 1330 can be selectively operable to control one or more of the electrical components 1350. For example, in some embodiments, the switch can be actuated by users to turn on and turn off the pump 1304 and/or a power source. In some embodiments, the switch 1330 can be selectively operable by users to control one or more operating conditions of the pump 1304 (e.g., to toggle through a plurality of operating states or levels of the pump 1304) in addition to or instead of powering on and powering off the wound dressing system 1300. For example, the switch 1330 can be electrically connected to a controller of the wound dressing system 1300 such that users can control various features of the pump 1304, including, for example, the negative pressure level delivered by the pump 1304 (e.g., pressure levels in the range of about −40 mmHg to −150 mmHg, among others), the type of pressure wave delivered by the pump 1304 (e.g., sinusoidal, sawtooth, and the like), and/or the operating mode of the pump 1304 (e.g., continuous or intermittent). For example, in some embodiments, one press of the switch 1330 can turn on the pump 1304 and cause the pump 1304 to deliver a target pressure of −40 mmHg, two presses of the switch 1330 after the pump 1304 has been turned on can cause the pump 1304 to deliver a target pressure of −80 mmHg, and holding the switch 1330 down for a predetermined amount of time (e.g., 2 seconds) can cause the pump 1304 to turn off. Other actuation combinations for controlling the wound dressing system 1300 with the switch 1330 are also appreciated. In some embodiments, a plurality of switches can be integrated with the wound dressing 1302 to control the wound dressing system 1300.
As shown in
The partially magnified perspective view of the corner in
As described previously,
As shown in
The film 1374 can be a clear plastic film, although any suitable material is appreciated, such as, for example, a Versapore film having a pore size diameter of about 2 μm. The film 1374 can be flexible. One or more edges of the film 1374 can provide a gas tight seal. The gas tight seal(s) can prevent air from the environment from leaking into the connector 1376. In some embodiments, the film 1374 can include top and bottom layers of a clear plastic film (or other suitable material, e.g., Versapore). One or more edges of the top and bottom layers can be thermally bonded to each other to provide a gas tight seal that can prevent air from the environment from leaking into the connector 1376. It should be appreciated that the gas tight seal along one or more edges (also referred to as one or more portions along a perimeter) of the connector 1376 can be sealed with any suitable process for any suitable film 1374 material. In some embodiments, the spacer 1372 can be freely movable within a chamber defined between the top and bottom layers of the film 1374.
As described above, the connector 1376 can define a flow path through which exhaust gas can flow. For example, in some embodiments, the flow path through the connector 1376 can extend between a first opening 1374a and a second opening 1374b of the film 1374. The portion of the flow path extending between the first and second openings 1374a, 1374b can include one or more channels defined within the connector 1376. In some embodiments, the one or more channels can define a generally tubular flow path that flows around the outside of the spacer 1372 but on the inside of the film 1374. For example, in some embodiments, the one or more channels can be defined by the open space between one or more surfaces (also referred to as sides) of the spacer 1372 and one or more interior surfaces of the film 1374. In some embodiments, the flow path can optionally include at least a portion of the spacer 1372. For example, in some embodiments, the flow path between the first and second openings 1374a, 1374b can extend through a portion of the spacer 1372 (e.g., all of it) in addition to around the spacer 1372. In some embodiments, the spacer 1372 can be positioned within the film 1372 such that the flow path between the first and second openings 1374a, 1374b only flows through the spacer. In some embodiments, the spacer 1372 can be disposed in the flow path to inhibit its occlusion. The second opening 1374b of the connector 1376 can be open to the environment 1390 outside the wound dressing to which the pump 1304 is integrated. The first opening 1374a of the film 1374 can connect to a pump or one or more other exhaust system 1370 features and components. In some embodiments, the first opening 1374a can be positioned on the top of the film 1374. In some embodiments, the first opening 1374a can be positioned through an edge of the film 1374.
In some embodiments, the exhaust system 1370 can optionally include an extension conduit 1380 having any suitable length. The extension conduit 1380 can be used to connect the connector 1376 to a source of negative pressure, such as, for example, the outlet 1304b of the pump 1304. Although not shown in
In some embodiments, the exhaust system 1370 does not include the optional extension conduit 1380. In such embodiments, the connector 1376 can be connected to the outlet 1304b of the pump 1304 such that the flow path of the exhaust system 1370 includes the flow path through the connector 1376.
As discussed above, the spacer 1372 can advantageously inhibit occlusion of the connector 1376. The arrangement of the connector 1376 can also advantageously prevent ingress of water, foreign bodies, dirt, and/or bacteria from getting inside the wound dressing through the flow path of the connector 1376.
The exhaust system 1370 can pass through any suitable location on a wound dressing through an opening in the wound dressing. For example, in some embodiments, a portion of the exhaust system 1370 can pass through a top layer of the wound dressing. As another example, in some embodiments, a portion of the exhaust system 1370 can pass through an edge of the wound dressing (e.g., a border of the wound dressing), such as, for example, between a top layer and a bottom layer of the wound dressing. For example,
In some embodiments, the exhaust system 1370 include one or more connectors 1376 and zero or more extension conduits 1380.
As shown in
In yet other embodiments, a portion of the extension conduit 1380 (e.g., an end of the extension conduit 1380) can attach to an edge 1374c of the film 1374. In some embodiments, the edge 1374c can include the first opening 1374a of the film 1374 as described above with reference to
In some embodiments, a portion of the connector 1376 and/or the extension conduit 1380 (e.g., the top and/or bottom layers 1393, 1392 of the film 1374) can include a layer of adhesive, for example a pressure sensitive adhesive, to seal the exhaust system 1370 (e.g., a portion of the exhaust conduit 1380 and/or a portion of the connector 1376) to a wound dressing. For example, in some embodiments, the connector 1376 can be sealed to one or more layers of the wound dressing (e.g., the cover layer, the wound contact layer, and the like).
In some embodiments, the top layer 1393 of the film 1374 can be substantially the same shape as the bottom layer 1392 of the film 1374. In some embodiments, the top layer 1393 and the bottom layer 1392 can be sealed together, for example, by heat welding and/or thermal bonding. In some embodiments, the bottom layer 1392 can be substantially flat and the top layer 1393 can be slightly larger than the bottom layer 1392 in order to accommodate the height of the spacer 1372 and seal to the bottom layer 1392. In other embodiments, the top layer 1393 and the bottom layer 1392 can be substantially the same size, and the layers can be sealed together approximately at the middle of the height of the spacer 1372. In some embodiments, the exhaust system 1370 can have a length in the range of about 0.3 cm to about 10 cm, although any suitable length is appreciated. In some embodiments, the bottom and top layers 1392, 1393 of the film 1374 can include at least one layer of a flexible film, and in some embodiments can be transparent. In some embodiments, the bottom layer 1392 and the top layer 1393 can be polyurethane, and can be liquid impermeable.
As described above, the connector 1376 can include a spacer 1372, such as the 3D fabric discussed above, positioned between the lower layer 1392 and the top layer 1393 of the film 1374. The spacer 1372 can be made of any suitable material, for example material resistant to collapsing in at least one direction, thereby enabling effective transmission of exhaust air therethrough. Instead of or in addition to the 3D fabric discussed above, some embodiments of the spacer 1372 can comprise a fabric configured for lateral wicking of fluid, which may comprise viscose, polyester, polypropylene, cellulose, or a combination of some or all of these, and the material may be needle-punched. Some embodiments of the spacer 1372 can comprise polyethylene in the range of 40-160 grams per square meter (gsm) (or about 40 to about 160 gsm), for example 80 (or about 80) gsm. Such materials may be constructed so as to resist compression.
As shown in
As shown in
In some embodiments, the non-return valve 1410 can optionally be integrated with the wound dressing 1302 and/or with one or more embedded electronic components 1350 (e.g., the pump 1304). The non-return valve 1410 can be, for example, sufficiently small to fit within the dimensional constraints of the wound dressing 1302. In some embodiments, the non-return valve 1410 can be optionally positioned within and/or embedded in the wound dressing 1302, such as, for example, in the electronics area 1361. To fit within the wound dressing 1302, the non-return valve 1410 can have any suitable size and shape. For example, in some embodiments, the non-return valve 1410 can have a height that is less than a thickness of the wound dressing 1302 (e.g., a thickness between the cover layer 1313 and the wound contact layer 1310). As another example, in some embodiments, the non-return valve 1410 can have a length that is less than a length of the electronics area 1361 of the wound dressing 1302.
So that the non-return valve 1410 can inhibit back flow while also efficiently allowing for out flow through the wound dressing system 1300, the non-return valve 1410 can advantageously have a low cracking pressure and a low resistance to out flow. A low cracking pressure and a low resistance to out flow can advantageously decrease the amount of power consumed during operation of the pump 1304 by decreasing the amount of resistance the pump 1304 must overcome to exhaust air. The use of a non-return valve 1410 can decrease the leak rate (also referred to as back flow) of the wound dressing system 1300 more than it decreases the pump rate of the wound dressing system 1300. For example, in some embodiments, using the non-return valve 1410 can result in a total leak rate reduction of about 8.4% compared to a total pump rate reduction of about 7%, thereby resulting in an energy savings of approximately 1.4% from the use of the non-return valve 1410 alone. In some embodiments, the cracking pressure of the non-return valve 1410 can range from about 350 Pa to 500 Pa for a flow rate of about 1 mL/min (e.g., a flow rate of exactly 1 mL/min), although any suitable cracking pressure is appreciated (and at any suitable flow rate), such as, for example, about 100 Pa, 250 Pa, 400 Pa, 550 Pa, or less than about 1,000 Pa for flow rates of about 1 mL/min, among others (e.g., any suitable cracking pressure between 0 Pa and 1,000 Pa). The cracking pressure according the aforementioned values corresponds to the threshold pressure drop to open and reseal of the non-return valve 1410 for air flows having rate of about 1 mL/min. It should be appreciated that any other standardized flow rates can be used as well. In some embodiments, the non-return valve 1410 may not decrease the flow rate through the pump by more than 100 mL/min. For example, in some embodiments, the non-return valve 1410 can decrease the flow rate through the pump between approximately 9.5 mL/min and approximately 24.5 mL/min, although other values of 100 mL/min or less are also appreciated. In some embodiments, the non-return valve 1410 can have an out flow resistance in the range of about 5.0 mL/min to about 30 mL/min (measured with a nominally fixed vacuum of 10.7 kPa below atmosphere), although any suitable out flow resistance is appreciated, such as, for example, an out flow resistance of about 9.5 mL/min to about 24.5 mL/min, an out flow resistance of about 9.5 mL/min, an out flow resistance of about 14.6 mL/min, an out flow resistance of about 24.5 mL/min, and an out flow resistance of less than about 100 mL/min, among others (as measured with a nominally fixed vacuum of 10.7 kPa below atmosphere). In some embodiments, the non-return valve 1410 does not prevent all back flow. For example, in some embodiments, the non-return valve 1410 can allow a negligible amount of air to leak into the wound dressing system 1300 through the outlet of the pump 1304. For example, in some embodiments, the leakage rate of the non-return valve 1410 can be negligible such that the pump 1304 and the non-return valve 1410 have a combined leak rate of about 10.0 mL/min or less, such as, for example, 1.0 mL/min or less, 2.0 mL/min or less, 3.0 mL/min or less, 4.0 mL/min or less, or 5.0 mL/min or less. In some embodiments, the wound dressing system 1300 can establish a target vacuum in 50 seconds or less with a non-return valve 1410 incorporated with the wound dressing 1302 and/or the exhaust system 1370. For example, in some embodiments, the wound dressing system 1300 can establish a target vacuum in about 5.1 seconds to 8.9 seconds, although any suitable time is appreciated.
The non-return valve 1410 positioned in the out flow path of the wound dressing system 1300 can be a mechanical self-activated valve that does not need and/or use power to operate. For example, in some embodiments, the non-return valve 1410 can be a reed valve or a duckbill valve, although any suitable mechanical one-way valve is appreciated, such as, for example, a ball valve or an umbrella valve, among others. Various views of duckbill non-return valves 1410 are illustrated in
As shown in
Further, although
Although not shown in
Disclosed embodiments relate to apparatuses and methods for wound treatment. In some embodiments, a negative pressure source is incorporated into a wound dressing apparatus so that the wound dressing and the negative pressure source are part of an integral or integrated wound dressing structure that applies the wound dressing and the negative pressure source simultaneously to a patient's wound. The negative pressure source and/or electronic components may be positioned between a wound contact layer and a cover layer of the wound dressing. A component may be used to prevent wound exudate from contacting the inlet of the negative pressure source.
In some embodiments, a source of negative pressure (such as a pump) and some or all other components of the TNP system, such as power source(s), sensor(s), connector(s), user interface component(s) (such as button(s), switch(es), speaker(s), screen(s), etc.) and the like, can be integral with the wound dressing. As is illustrated in
In some embodiments, the dressing can include the power source and other components, such as electronics, on and/or incorporated into the dressing and can utilize a wound contact layer and a first spacer layer within the dressing. The wound contact layer can be in contact with the wound. The wound contact layer can include an adhesive on the patient facing side for securing the dressing to the skin surrounding the wound or on the top side for securing the wound contact layer to a cover layer or other layer of the dressing. In operation, the wound contact layer can provide unidirectional flow so as to facilitate removal of exudate from the wound while blocking or substantially preventing exudate from returning to the wound. The first spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. Further, an absorbent layer (such as layer 3240) for absorbing and retaining exudate aspirated from the wound can be utilized. In some embodiments, the absorbent includes a shaped form of a superabsorber layer with recesses or compartments for the pump, electronics, and accompanying components. These layers can be covered with one or more layers of a film or cover layer (or a first cover layer). The first cover layer can include a filter set that can be positioned within one of the recesses. The filter can align with one of the at least one recesses of the absorbent layer, and the filter can include hydrophobic material to protect the pump and/or other components from liquid exudates. The filter can block fluids while permitting gases to pass through. Optionally, one or more of the pump, electronics, switch and battery can be positioned on top of the first cover layer as illustrated in
In some embodiments, the pump and/or other electronic components can be configured to be positioned adjacent to or next to the absorbent and/or transmission layers so that the pump and/or other electronic components are still part of a single apparatus to be applied to a patient with the pump and/or other electronics positioned away from the wound site.
The dressing can comprise a wound contact layer 3310, a spacer layer 3311, an absorbent layer 3212, 3322, a moisture vapor permeable film or cover layer 3213, 3313 positioned above the wound contact layer, spacer layer, absorbent layer, or other layers of the dressing. The wound contact layer can be configured to be in contact with the wound. The wound contact layer can include an adhesive on the patient facing side for securing the dressing to the surrounding skin or on the top side for securing the wound contact layer to a cover layer or other layer of the dressing. In operation, the wound contact layer can be configured to provide unidirectional flow so as to facilitate removal of exudate from the wound while blocking or substantially preventing exudate from returning to the wound.
The wound contact layer 3310 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 3310 has a lower surface and an upper surface. The perforations preferably comprise through holes in the wound contact layer 3310 which enable fluid to flow through the layer 3310. The wound contact layer 3310 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 0.025 mm to 1.2 mm 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 3310 may help maintain the integrity of the entire dressing 3200, 3300 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 3310 may also act as a carrier for an optional lower and upper adhesive layer (not shown). For example, a lower pressure sensitive adhesive may be provided on the lower surface of the wound dressing 3200, 3300 whilst an upper pressure sensitive adhesive layer may be provided on the upper surface of the wound contact layer. The pressure sensitive adhesive, which may be a silicone, hot melt, hydrocolloid or acrylic based adhesive or other such adhesives, may be formed on both sides or optionally on a selected one or none of the sides of the wound contact layer. When a lower pressure sensitive adhesive layer is utilized it may be helpful to adhere the wound dressing 3200, 3300 to the skin around a wound site. In some embodiments, the wound contact layer may comprise perforated polyurethane film. The lower surface of the film may be provided with a silicone pressure sensitive adhesive and the upper surface may be provided with an acrylic pressure sensitive adhesive, which may help the dressing maintain its integrity. In some embodiments, a polyurethane film layer may be provided with an adhesive layer on both its upper surface and lower surface, and all three layers may be perforated together.
A layer 3311 of porous material can be located above the wound contact layer 3310. As used herein, the terms porous material, spacer, and/or transmission layer can be used interchangeably to refer to the layer of material in the dressing configured to distribute negative pressure throughout the wound area. This porous layer, or transmission layer, 3311 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 3311 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 3311 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 3311 may be formed of a material having a three-dimensional structure. For example, a knitted or woven spacer fabric (for example Baltex 7970 weft knitted polyester) or a non-woven fabric could be used.
The spacer layer assists in distributing negative pressure over the wound site and facilitating transport of wound exudate and fluids into the wound dressing. In some embodiments, the spacer layer can be formed at least partially from a three-dimensional (3D) fabric.
In some embodiments, the transmission layer 3311 comprises a 3D polyester spacer fabric layer including a top layer (that is to say, a layer distal from the wound-bed in use) which is a 84/144 textured polyester, and a bottom layer (that is to say, a layer which lies proximate to the wound bed in use) which is a 10 denier flat polyester and a third layer formed sandwiched between these two layers which is a region defined by a knitted polyester viscose, cellulose or the like monofilament fiber. Other materials and other linear mass densities of fiber could of course be used.
Whilst reference is made throughout this disclosure to a monofilament fiber it will be appreciated that a multistrand alternative could of course be utilized. The top spacer fabric thus has more filaments in a yarn used to form it than the number of filaments making up the yarn used to form the bottom spacer fabric layer.
This differential between filament counts in the spaced apart layers helps control moisture flow across the transmission layer. Particularly, by having a filament count greater in the top layer, that is to say, the top layer is made from a yarn having more filaments than the yarn used in the bottom layer, liquid tends to be wicked along the top layer more than the bottom layer. In use, this differential tends to draw liquid away from the wound bed and into a central region of the dressing where the absorbent layer 3212, 3322 helps lock the liquid away or itself wicks the liquid onwards towards the cover layer 3213, 3313 where it can be transpired.
Preferably, to improve the liquid flow across the transmission layer 3311 (that is to say perpendicular to the channel region formed between the top and bottom spacer layers, the 3D fabric may be treated with a dry cleaning agent (such as, but not limited to, Perchloro Ethylene) to help remove any manufacturing products such as mineral oils, fats or waxes used previously which might interfere with the hydrophilic capabilities of the transmission layer. In some embodiments, an additional manufacturing step can subsequently be carried in which the 3D spacer fabric is washed in a hydrophilic agent (such as, but not limited to, Feran Ice 30 g/l available from the Rudolph Group). This process step helps ensure that the surface tension on the materials is so low that liquid such as water can enter the fabric as soon as it contacts the 3D knit fabric. This also aids in controlling the flow of the liquid insult component of any exudates.
Further, an absorbent layer (such as layer 3212) 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 3212. In some embodiments, the absorbent includes a shaped form of a superabsorber layer.
A layer 3212, 3322 of absorbent material is provided above the transmission layer 3311. The absorbent material, which comprise a foam or non-woven natural or synthetic material, and which may optionally comprise a super-absorbent material, forms a reservoir for fluid, particularly liquid, removed from the wound site. In some embodiments, the layer 10 may also aid in drawing fluids towards the backing layer 3213, 3313.
The material of the absorbent layer 3212, 3322 may also prevent liquid collected in the wound dressing from flowing freely within the dressing, and preferably acts so as to contain any liquid collected within the dressing. The absorbent layer 3212, 3322 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 3212, 3322 may typically be manufactured from ALLEVYN™ foam, Freudenberg 114-224-4 or Chem-Posite™ M11C-450. In some embodiments, the absorbent layer 3212, 3322 may comprise a composite comprising superabsorbent powder, fibrous material such as cellulose, and bonding fibers. In a preferred embodiment, the composite is an airlaid, thermally-bonded composite.
In some embodiments, the absorbent layer 3212, 3322 is a layer of non-woven cellulose fibers having super-absorbent material in the form of dry particles dispersed throughout. Use of the cellulose fibers introduces fast wicking elements which help quickly and evenly distribute liquid taken up by the dressing. The juxtaposition of multiple strand-like fibers leads to strong capillary action in the fibrous pad which helps distribute liquid. In this way, the super-absorbent material is efficiently supplied with liquid. The wicking action also assists in bringing liquid into contact with the upper cover layer to aid increase transpiration rates of the dressing.
The wound dressing layers of the electronics area and the absorbent layer can be covered by one continuous cover layer or backing layer 3213. As used herein, the terms cover layer and/or backing layer can be used interchangeably to refer to the layer of material in the dressing configured to cover the underlying dressing layers and seal to the wound contact layer and/or the skin surrounding the wound. In some embodiments, the cover layer can include a moisture vapor permeable material that prevents liquid exudate removed from the wound and other liquids from passing through, while allowing gases through.
The backing layer 3213, 3313 is preferably gas impermeable, but moisture vapor permeable, and can extend across the width of the wound dressing 100. The backing layer 3213, 3313, 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 3213, 3313 and a wound site where a negative pressure can be established. The backing layer 3213, 3313 is preferably sealed to the wound contact layer 3310 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 3213, 3313 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 3213, 3313 preferably comprises two layers; a polyurethane film and an adhesive pattern spread onto the film. The polyurethane film is preferably moisture vapor permeable and may be manufactured from a material that has an increased water transmission rate when wet. In some embodiments, the moisture vapor permeability of the backing layer increases when the backing layer becomes wet. The moisture vapor permeability of the wet backing layer may be up to about ten times more than the moisture vapor permeability of the dry backing layer.
The electronics area 3261 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 3261 can include a button or switch 3211 as shown in
The absorbent area 3260 can include an absorbent material 3212 and can be positioned over the wound site. The electronics area 3261 can be positioned away from the wound site, such as by being located off to the side from the absorbent area 3260. The electronics area 3261 can be positioned adjacent to and in fluid communication with the absorbent area 3260 as shown in
In some embodiments, additional layers of dressing material can be included in the electronics area 3261, the absorbent area 3260, or both areas. In some embodiments, the dressing can comprise one or more spacer layers and/or one or more absorbent layer positioned above the wound contact layer 3310 and below the cover layer 3213, 3313 of the dressing.
As shown in
The absorbent area 3360 of the dressing can include a second spacer layer 3311 or lower spacer layer and an absorbent layer 3322 positioned above the wound contact layer 3310. The second spacer layer 3311 can allow for an open air path over the wound site. The absorbent layer 3322 can include a super absorber positioned in the absorbent area 3360 of the dressing. The absorbent layer 3322 can retain wound fluid within thereby preventing fluid passage of wound exudates into the electronics area 3361 of the dressing. The wound fluids can flow through the wound contact layer 3310, to the lower spacer layer 3311, and into the absorbent layer 3322. The wound fluids are then spread throughout the absorbent layer 3322 and retained in the absorbent layer 3322 as shown by the directional arrows for wound fluids in
The electronics area 3361 of the dressing can include a plurality of layers of spacer material 3351. In some embodiments, the electronic components 3350 can be embedded within the plurality of layers of spacer material 3351. The layers of spacer material can optionally have recesses or cut outs to embed the electronic components within whilst providing structure to prevent collapse. As described above, the electronic components 3350 can optionally include a pump, a power source, a controller, and/or an electronics package, although any suitable electronic component is appreciated. A partition 3362 can optionally be positioned between the absorbent area 3360 and the electronics area 3361. The partition 3362 can separate the absorbent layer 3322 and lower air flow spacer layer 3311 from the electronic housing segment of the dressing in the electronic area. The partition 3362 can prevent wound fluid (e.g., wound exudate) from entering the electronic housing section of the dressing. In some embodiments, the partition can be a non-porous dam or other structure. The non-porous dam 3362 can include a cyanoacrylate adhesive bead or a strip of silicone. The air pathway through the dressing is shown in
As shown in
In some embodiments, the component 3510 can be made of a hydrophobic material that repels wound exudate, thereby inhibiting the ingress of fluid into the component 3510 and ultimately the pump 3304. In some embodiments, component 3510 can be a hydrophobic coated material. In some embodiments, the component 3510 can be made of a porous material. The pores can be small enough to inhibit the ingress of fluid through the component 3510 due to capillary action (i.e., from surface tension of the wound exudate against the component 3510) and the pressure differential between the environment and the wound dressing, but large enough to permit the passage of air. For example, in some embodiments, the component 3510 can be made of a material that has a pore size in the range of approximately 20 microns to approximately 100 microns. For example, in some embodiments, the material of the component 3510 can have a pore size of approximately 30 microns. In some embodiments, the material of the component 3510 can have a pore size of approximately 10 microns. However, it will be understood that any suitable pore size is appreciated. In some embodiments, the component can be a foam or a foam-like material. The hydrophobic nature of the material of the component 3510 and/or its pore size can function to inhibit the flow of wound exudate from the wound dressing 3302 to the pump 3304. The component 3510 thereby inhibits the pump 3304 in the wound dressing system 3300 from discharging wound exudate from the wound dressing 3302.
As described above, the material of the component 3510 can be porous. In some embodiments, the plurality of flow paths through the component 3510 can be defined by a series of sequentially connected pores formed in the material of the component 3510, beginning with pore(s) in fluid communication with an interior of the wound dressing 3302 and positioned on the exterior of the component 3510 and ending with pore(s) in fluid communication with the pump 3304 and positioned on the interior of the component 3510. Pores advantageously provide flow path redundancy because of their lattice arrangement and interconnected structure. The plurality of flow paths through the component 3510 that connect the first pore(s) in fluid communication with an interior of the wound dressing 3302 and the last pore(s) in fluid communication with the pump 3304 can be straight and/or tortuous. A group of open pores can effectively create one or more larger flow channels through the component 3510 that can sizably adjust as one or more occlusions materialize inside and/or outside the component 3510. In some embodiments, one or more pores can define one or more overlapping flow paths. For example, if one or more adjacent and/or neighboring pores of an open pore become occluded by wound exudate, the open pore can maintain an open path from the wound dressing 3302 to the pump 3304 by helping to redefine one or more flow paths around the one or more occluded pores. It will be appreciated that the plurality of flow paths through the component can be formed with any suitable structure. For example, in addition to or in lieu of pores, the plurality of flow paths can be formed by one or more channels extending through the component 3510.
In some embodiments, the component 3510 can be a porous polymer component. The porous polymer component can be machined and/or molded (e.g., injection molded) into any suitable shape. For example,
The components 3510 shown in
Although not shown in
In some embodiments, the component 3510 does not reduce the pump flow rate by more than 50 mL/min. For example, in some embodiments, the component 3510 can reduce the pump flow rate in the range of 15 mL/min to 35 mL/min (e.g., from 21 mL/min to 31 mL/min). In some embodiments, the component 3510 does not reduce the free performance of the pump by more than 10%. For example, in some embodiments, the component 3510 can reduce the free performance of the pump in the range of 4% to 6%.
In some embodiments, the component 3510 can be a micro porous membrane attached to a pump inlet. In some embodiments, the membrane can be formed into the shape of a pouch to fit over and attach to the pump inlet. A 3d spacer (e.g., fabric) can be disposed in the pouch to inhibit the membrane from collapsing. In some embodiments, the pouch can be elongate in form, but it will be appreciated that the pouch can take on any suitable form. The membrane can be hydrophobic to repel fluid (e.g., wound exudate) and have a porosity that inhibits fluid ingress into the pump inlet due to capillary action. For example, in some embodiments, the micro porous membrane can be made of Versapore having a 0.2 μm pore size (Pall).
In some embodiments, the component 3510 can be one or more lengths of fine bore tubing with a plurality of holes disposed along their lengths. The one or more lengths of fine bore tubing can form one or more loops between a pump inlet and a wound dressing. As another example, the one or more lengths of fine bore tubing can extend from the pump inlet to one or more different points in the wound dressing, similar to the way in which the two components 3510 in
In some embodiments, the component 3510 is designed so that a significant pressure drop is avoided by its use. In this way, the component 3510 prevents the pump 3304 from having to work harder and consume more power from any added resistance it may add to the flow path from the wound dressing to the environment through the pump 3304.
In some embodiments, the component 3710 can be pushed onto the pump inlet. This can be a friction fit. The port of the component 3710 that receives a portion of the pump inlet can be sized and shaped to be a complementary fit around the pump inlet. In some embodiments, the component 3710 can be bonded onto the pump inlet using a silicone sealant or any other sealant or sealing technique. In some embodiments, the electronics unit can be embedded within layers of the dressing in the electronics area 3361. In some embodiments, the layers of the dressing in the electronics area 3361 can include cutouts or recesses into which the electronics unit 3700 can be placed.
The component 3710 can be provided on the inlet of the pump 3327. In some embodiments, the hydrophobicity of the component 3710 can keep the inlet to the pump free of exudate. In some embodiments, the component 3710 can be in contact with and/or in fluid communication with superabsorbent and/or absorbent material. In this configuration, the component 3710 can prevent liquid from being pulled through to the inlet of the pump when negative pressure is applied. The component 3710 can be made of a material with a pore size larger than the pore size of traditional hydrophobic filters and liquid could get through if the material of the component were by itself in contact with water. However, the hydrophobicity of the hydrophobic component 3710 with a pore size as described herein can be in contact with the superabsorber and/or absorbent material and can prevent exudate from being pulled through the inlet of the pump when negative pressure is applied.
In some embodiments, the component 3710 can have a 3-dimensional shape and circumferentially surrounds the pump inlet. The 3-dimensional shaped component 3710 can have a width, height, and/or length dimension that is greater than the width, height, and/or length of the pump inlet 3304a. In some embodiments, the component 3710 can be a cuboid or generally cuboid shape as shown in
All of the features disclosed in this specification (including any accompanying exhibits, claims, abstract and drawings), and/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 and/or steps are mutually exclusive. The disclosure is not restricted to the details of any foregoing embodiments. The disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the principles and features disclosed herein. Certain embodiments of the disclosure are encompassed in the claim set listed below or presented in the future.
Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57. This application is a continuation-in-part of co-pending U.S. application Ser. No. 17/685,251, filed Mar. 2, 2022, which is a continuation application of U.S. application Ser. No. 16/096,266, filed Oct. 24, 2018 and now issued as U.S. Pat. No. 11,285,047, which is a U.S. national stage application of International Patent Application No. PCT/EP2017/059883, filed Apr. 26, 2017, which claims priority to U.S. Provisional Application No. 62/327,676, filed Apr. 26, 2016. This application is also a continuation-in-part of co-pending U.S. application Ser. No. 18/207,601, filed Jun. 8, 2023, which is a divisional of U.S. application Ser. No. 16/082,884, filed Sep. 6, 2018 and now issued as U.S. Pat. No. 11,723,809, which is a U.S. national stage application of International Patent Application No. PCT/EP2017/055225, filed on Mar. 6, 2017, which claims priority to U.S. Provisional Application No. 62/304,790, filed Mar. 7, 2016, U.S. Provisional Application No. 62/305,926, filed Mar. 9, 2016, U.S. Provisional Application No. 62/304,910, filed Mar. 7, 2016, and U.S. Provisional Application No. 62/327,537, filed Apr. 26, 2016. The disclosures of all these prior applications are hereby incorporated herein by reference in their entireties and are to be to be considered a part of this specification.
| Number | Date | Country | |
|---|---|---|---|
| 62327676 | Apr 2016 | US | |
| 62304790 | Mar 2016 | US | |
| 62305926 | Mar 2016 | US | |
| 62304910 | Mar 2016 | US | |
| 62327537 | Apr 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16082884 | Sep 2018 | US |
| Child | 18207601 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16096266 | Oct 2018 | US |
| Child | 17685251 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17685251 | Mar 2022 | US |
| Child | 18902471 | US | |
| Parent | 18207601 | Jun 2023 | US |
| Child | 18902471 | US |
