Wound dressing

ES 2 571 332 T3

DESCRIPTION

Wound dressing

The present invention relates to an apparatus for bandaging a wound and a method of making a wound dressing. In particular, but not exclusively, the present invention relates to a wound dressing that is used during topical negative pressure therapy (PNT) in which the wound dressing itself acts as a waste repository where it is collected and stored. wound exudate removed from a wound area.

There is considerable prior art related to the provision of apparatus and methods of using the same for applying topical negative pressure therapy (PNT) to wounds in conjunction with other therapeutic processes designed to enhance the effects of PNT therapy. Examples of such prior art are mentioned and briefly described below.

PNT therapy helps to close and heal wounds by reducing tissue edema; favoring blood flow; stimulating the formation of granulation tissue; eliminating excessive exudates, and can reduce the bacterial load and therefore the infection in the wound. In addition, PNT therapy allows the wound to be less exposed to external contaminants and promotes faster healing.

Certain prior art apparatuses and methods are generally only applicable to hospitalized patients, since the apparatus used is complex and requires personnel with specialized knowledge in its use and maintenance, and is also relatively heavy and bulky, and is not adapted for a patient easily move it out of the hospital environment, for example.

Some patients with relatively less severe injuries that do not require permanent hospitalization, for example, but would still benefit from prolonged use of PNT therapy, could be treated at home or at work if they had access to a PNT therapy device that could be easily maintained and transported. For this purpose, a portable PNT therapy unit is known, which a patient can carry or wear attached to a belt or harness. In this way negative pressure can be applied to a wound area.

During PNT therapy, a portable or non-portable therapy unit generates negative pressure in the wound area. As fluid, including air as well as wound exudate material, is withdrawn from the wound area, it must be collected away from the wound area. In therapy units known in the art, collection and storage of wound exudate material is typically accomplished by a waste reservoir connected to a pump unit of the therapy unit. However, the use of a reservoir can result in the therapy unit apparatus itself being quite bulky and expensive to manufacture. Additionally, changing a reservoir or bag into a reservoir where exudate is collected can be a time-consuming and relatively unsanitary process.

WO2007 / 030601 describes the use of a micropump system to apply subatmospheric pressure to the wound.

US 2007/0027414 describes a negative pressure laminated wound dressing system and its method of use.

WO 2009/124100 describes a composite wound dressing for use with a micropump system.

WO 2008/064502 relates to a device for treating a low pressure wound.

An object of the present invention is to at least partially mitigate the problems mentioned above.

An objective of certain embodiments of the present invention is to provide a wound dressing that exhibits an increased ability to absorb wound exudate and reduce the frequency with which dressings must be changed.

The invention is as claimed in the claims.

According to a first aspect of the present invention, there is provided a wound dressing apparatus designed to apply topical negative pressure to a wound area, comprising:

a transmission layer permeable to liquids and gases;

an absorbent layer to absorb wound exudate;

a gas-impermeable cover layer overlying the absorbent layer and the transmission layer, the cover layer comprising a hole connected to the transmission layer; and

ES 2 571 332 T3 at least one element configured to reduce the speed at which wound exudate moves toward the hole when negative pressure is applied to the hole.

Some embodiments of the present invention offer the advantage that a wound dressing can be used to collect wound exudate generated during a negative pressure therapy process, while extending the useful life of the dressing by making the wound exudate perspire a water component. A remote pump can be connected to the wound dressing and reused while the wound dressing itself is used to collect wound exudate and can be discarded after use.

The embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 illustrates a wound dressing;

Figure 2 illustrates a top view of a wound dressing;

Figure 3 illustrates a top view of a wound dressing including deflector elements;

Figure 4 illustrates a top view of an additional wound dressing including deflector elements;

Figure 5 illustrates a deflector element according to one embodiment;

Figure 6 illustrates a top view of a wound dressing including a single deflector element;

Figure 7 illustrates a top view of a wound dressing including an air channel;

Figure 8 illustrates a top view of a wound dressing including two air channels;

Figure 9 illustrates a top view of a wound dressing including two holes in a cover layer engaged through a fluid transmission passage;

Figure 10 illustrates one embodiment of the fluid transmission passage;

Figure 11 illustrates a top view of a suction port;

Figure 12 illustrates a suction port that includes a filter element;

Figure 13 illustrates a further suction port that includes a filter element; e Figure 14 illustrates a variety of exemplary deflector element configurations in a wound dressing;

Figure 15 illustrates an exemplary pathway configuration in a transmission layer of a wound dressing;

Figure 16 illustrates a top view of a wound dressing including an elongated hole in a covering layer;

Figure 17 illustrates one embodiment of a wound management system; and Figures 18 AD illustrate the use and application of one embodiment of a wound management system in a patient.

In the drawings, the same reference number designates equal parts.

Figure 1 illustrates a cross section of a wound dressing 100 according to one embodiment of the invention. A top plan view of the wound dressing 100 is illustrated in Figure 2 and the line AA indicates the location of the cross-section shown in Figure 1. It will be understood that Figure 1 illustrates a general schematic view of an apparatus 100 . It will be understood that embodiments of the present invention are generally applicable for use in topical negative pressure (PNT) systems. Briefly, negative pressure wound therapy aids in the closure and healing of various hard-to-heal wounds by reducing tissue edema; favoring blood flow and the formation of granular tissue; removing excess exudate and can reduce the bacterial load (and therefore the risk of infection). In addition, the therapy helps the wound to be less exposed to external contaminants, which leads to faster healing. PNT systems can also aid in the healing of surgically closed wounds by evacuating fluids and assisting in stabilizing the tissue in the juxtaposed closed position. An additional beneficial use of PNT can be found in grafts and flaps where evacuation of excess fluid is important and where the graft is required to be in close proximity to the tissue to ensure viability.

The wound dressing 100 can be located over a wound area to be treated. The dressing 100 forms a sealed cavity over the wound area. It will be noted that throughout this specification reference is made

ES 2 571 332 T3 to a wound. In this sense, it should be understood that the term wound is to be interpreted broadly and includes open and closed wounds where the skin has been torn, cut or punctured or where trauma causes a contusion. Thus, a wound is broadly defined as any region of damaged tissue that may or may not produce fluid. Examples of such wounds include, but are not limited to, incisions, tears, abrasions, bruises, burns, diabetic ulcers, decubitus ulcers, stomata, surgical wounds, trauma and varicose ulcers or the like.

It is envisaged that the negative pressure range for the apparatus made in the present invention may be between 20 mm Hg and -200 mm Hg (it should be noted that these pressures are relative to normal atmospheric pressure, therefore -200 mm Hg it would be roughly 560 mm Hg in practical terms). Correctly, the pressure range can be between -40 mm Hg and -150 mm Hg. Alternatively, a pressure range of up to -75 mm Hg, down to -80 mm Hg, or greater than -80 mm Hg can be used. A pressure range of less than -75 mm Hg can also be used wisely. Alternatively, a pressure range of greater than -100 mm Hg or greater than -150 mm Hg can be used.

In some embodiments, it may be preferable that the wound area is partially or completely filled with a wound filling material. This wound filling material is optional, but may be desirable in certain wounds, eg deeper wounds. The wound filling material can be used in addition to the wound dressing 100. The wound filling material can generally comprise a compliant, porous material, for example foam (including cross-linked foams) and gauze. Preferably, the wound filling material is sized and molded to fit within the wound area to fill any void spaces. The wound dressing 100 can also be placed over the wound area and over the wound filling material overlying the wound area. When using wound filling material, once the wound dressing 100 is sealed over the wound area, PNT is transmitted from a pump through the wound dressing 100, through the wound filling material, and towards the wound area. This negative pressure draws wound exudate and other fluids or secretions from the wound area.

It will be appreciated that according to certain embodiments of the present invention, the supplied pressure may be regulated over a period of time according to one or more desired or pre-defined pressure profiles. For example, such a profile may include regulating the negative pressure between two predetermined negative pressures P1 and P2 so that the pressure remains substantially constant at P1 for a predetermined period of time and is then adjusted by appropriate means, such as variable pumping, or by restricting the flow of fluid, or similar means, at a new predetermined pressure p2 where the pressure can be kept substantially constant for a predetermined period of time T2. Two, three or four or more preset pressure values ​​and their respective time periods can optionally be used. Suitably, more complex amplitude / frequency waveforms of pressure flow profiles can also be offered, eg sinusoidal, sawtooth, systolic-diastolic or the like, etc.

As illustrated in Figure 1, a bottom surface 101 of the wound dressing 100 is provided by an optional wound contact layer 102. The wound contact layer 102 may be a polyurethane layer or a layer of polyurethane. polyethylene or other flexible layer that is perforated, for example, by a hot piercing process, a laser ablation process, an ultrasound process or any other way, or by making it permeable to liquids or gases in any other way. The wound contact layer has a lower surface 101 and an upper surface 103. The perforations 104 are through holes in the wound contact layer, which allow fluid to flow through the layer. The wound contact layer helps prevent tissue from growing into the other wound dressing material. The perforations are small enough to meet this requirement and still allow fluid to pass. For example, perforations formed as slits or holes that are sized within the range of 0.025mm and 1.2mm are considered small enough to help prevent tissue growth within the wound dressing while allowing wound exudate flows into the dressing. The wound contact layer helps hold the entire wound dressing together and helps create a tight seal around the absorbent pad to maintain negative pressure on the wound. The wound contact layer also acts as a transport vehicle for an optional upper and lower adhesive layer (not shown). For example, a lower pressure sensitive adhesive can be provided on the lower surface 101 of the wound dressing while an upper pressure sensitive adhesive layer can be provided on the upper surface 103 of the wound contact layer. The pressure sensitive adhesive, which can be a silicone, hot melt, hydrocolloid or acrylic-based adhesive or other type of adhesive, can be formed on both sides or optionally on one of the selected sides or on neither side. of the wound contact layer. When a lower pressure sensitive adhesive layer is used, this helps the wound dressing adhere to the skin around the wound area.

A layer 105 of porous material is located above the wound contact layer. This porous layer, or transmission layer, 105 allows the transmission of fluid including liquids and gases from a wound area to upper layers of the wound dressing. In particular, the transmission layer 105 ensures that an open air channel is maintained to transmit negative pressure over the wound area even when the absorbent layer has absorbed substantial amounts of exudates. The layer should remain open under the typical pressures that will be applied during the negative pressure wound therapy described above, in order for the

The entire wound area receives a uniform negative pressure. Layer 105 is formed of a material having a three-dimensional structure that could comprise an open cell foam, a knitted or woven spacer fabric (eg Baltex 7970 weft knit polyester), or a nonwoven fabric.

Successfully, the transmission layer comprises a 3D polyester spacer fabric layer that includes a top layer (i.e., a distal layer of the wound bed under treatment) that is 84/144 textured polyester, and a bottom layer (i.e. a layer that is close to the wound bed being treated) which is a 100 denier flat polyester and a third layer sandwiched between these two layers, which is a region defined by a knitted polyester viscose, cellulose, or similar monofilament fiber. Of course, other materials and other linear fiber mass densities could be used.

Although reference is made throughout this description to a monofilament fiber, it will be appreciated that it is possible to use a multi-stranded alternative.

The upper spacer fabric therefore has more filaments in a yarn used to form it than the number of filaments that make up the yarn used to form the lower spacer fabric layer.

This difference between the number of filaments in the separate layers helps to control the flow of moisture through the transmission layer. In particular, by having a greater number of filaments in the upper layer, that is, the upper layer is composed of a yarn that has more filaments than the yarn used in the lower layer, the liquid tends to be extracted more in the upper layer than in the bottom layer. In practice, this difference tends to cause fluid to leak from the wound bed into a central region of the dressing where the absorbent layer helps to enclose said fluid or causes fluid to drain further into the covering layer. where it can be perspired.

Successfully, to improve liquid flow through the transmission layer (i.e. perpendicular to the channel region formed between the upper and lower spacer layers, the 3D fabric is treated with a dry cleaning agent (such as be, but not limited to, tetrachlorethylene) to help remove any manufacturing products, such as previously used mineral oils, greases and / or waxes, that could interfere with the hydrophilic capabilities of the transmission layer. Successfully, a further manufacturing step can be carried out later in which the 3D spacer cloth is washed in a hydrophilic agent (such as, but not limited to, Feran Ice 30g / l available from the Rudolph Group). This step in the process helps ensure that the surface tension in the materials is so low that liquid, such as water, can penetrate the fabric as soon as it comes into contact with the 3D knit fabric. This also helps control the flow of the damaging liquid component of any exudate.

A layer 110 of absorbent material is provided on top of the transmission layer 105. The absorbent material which may be a foam or natural or synthetic nonwoven material and which may optionally be or include a superabsorbent material forms a reservoir for fluids, particularly liquids, removed from the wound area, and draws said fluids into a cover layer 140. The absorbent layer material also prevents fluid collected in the wound dressing from flowing out in a rush. The absorbent layer 110 also helps to distribute the fluid throughout the layer through an extraction action, such that the fluid is drawn from the wound area and stored throughout the absorbent layer. This prevents them from agglomerating by areas in the absorbent layer. The capacity of the absorbent material should be sufficient to control the flow rate of exudate from a wound when negative pressure is applied. Because in practice the absorbent layer experiences negative pressures, the absorbent layer material is selected to absorb liquid under such circumstances. There are a variety of materials capable of absorbing liquid under negative pressure, for example, superabsorbent materials. Absorbent layer 110 can typically be made of aLlEVYN ™, Freudenberg 114-224-4 and / or Chem-Posite ™ 11C-450 foam.

Successfully, the absorbent layer is a layer of nonwoven cellulose fibers containing superabsorbent material in the form of dispersed drying particles. The use of cellulose fibers introduces quick extraction elements that help to distribute the liquid absorbed by the dressing quickly and evenly. The juxtaposition of multiple strand fibers causes strong capillary action on the fibrous pad, which helps to distribute the liquid. In this way, the superabsorbent material is efficiently supplied with liquid. Furthermore, all regions of the absorbent layer receive the liquid.

The pull-out action also helps by bringing the liquid into contact with the top covering layer to help increase the speed of perspiration of the dressing.

The extraction action also helps to send fluid downward toward the wound bed when exudation is reduced or stopped. This delivery process helps keep the transmission layer and the lower wound bed region in a moist state that helps prevent crusting of the dressing (which can lead to clogging) and helps maintain an optimal environment. for wound healing.

Suitably, the absorbent layer can be an air-laid material. Optionally, hot melt fibers can be used to help hold the pad structure together. It will be appreciated that instead of or in addition to using superabsorbent particles, fibers may be used.

ES 2 571 332 T3 superabsorbents according to certain embodiments of the present invention. An example of a suitable material is the Chem-Posite ™ 11 C product marketed by Emerging Technologies Inc (ETi) in the United States.

Optionally, according to certain embodiments of the present invention, the absorbent layer may include stable synthetic fibers and / or stable bicomponent fibers and / or stable natural fibers and / or superabsorbent fibers. The fibers of the absorbent layer may be secured by latex bonding or thermal bonding or hydrogen bonding, or a combination of any bonding technique or other fastening mechanism. Successfully, the absorbent layer is formed by fibers that act to enclose the superabsorbent particles within the absorbent layer. This helps to ensure that the superabsorbent particles do not leave the absorbent layer and move into an underlying wound bed. This is especially useful since when negative pressure is applied the absorbent pad tends to sag and this action would push the superabsorbent particulate matter into the wound bed were it not for the fibrous structure of the absorbent layer keeping it enclosed.

The absorbent layer comprises a multi-fiber layer. The fibers are aptly of the strand type and made of cellulose, polyester, viscose or a similar material. Successfully, the absorbent drying particles are distributed throughout the absorbent layer, ready to be used. Successfully, the absorbent layer comprises a cellulose fiber pad and a plurality of superabsorbent particles. Aptly, the absorbent layer is a nonwoven layer of randomly oriented cellulose fibers.

The superabsorbent particles / fibers can be made, for example, from sodium polyacrylate or carboxymethylcellulose materials or the like or from any material capable of absorbing several times its own weight in liquid. Successfully, the material can absorb more than five times its own weight of 0.9% w / w saline solution, etc. Rightly, the material is capable of absorbing more than 20 times its own weight of a 0.9% w / w saline solution, etc. Rightly, the material is capable of absorbing more than 30 times its own weight of a 0.9% w / w saline solution, etc.

Successfully, the superabsorbent particles are highly hydrophilic and trap fluid as it enters the dressing, swelling to the touch. An equilibrium is reached within the center of the dressing whereby moisture passes from the superabsorbent to the surrounding drying zone and, when it touches the top film, the film moves and fluid vapor begins to perspire. A moisture gradient is established within the dressing to continuously remove fluid from the wound bed and ensure that the dressing does not become heavy with exudate.

Successfully, the absorbent layer includes at least one through hole positioned so as to lie beneath the suction port. As illustrated in Figure 1, a single through hole can be used to create an opening underlying port 150. It will be appreciated that multiple openings can be used as an alternative. Furthermore, if according to some embodiments of the present invention more than one port is used, one or more openings may be made in the superabsorbent layer aligned with each respective port. Although not essential for certain embodiments of the present invention, the use of through holes in the superabsorbent layer provides a fluid flow path that is especially unobstructed and this is useful in certain circumstances.

Where an opening is provided in the absorbent layer, the thickness of the layer itself will act as an insulator, separating any overlapping layers from the upper surface (i.e., the surface facing the opposite side of the wound being treated) of the layer. transmission 105. An advantage of this is that the port filter thus disengages from the material of the transmission layer. This helps reduce the chances of the filter becoming soggy and thus clogging and blocking any other action.

The use of one or more through holes in the absorption layer also has the advantage that during use, if the absorbent layer contains a gel-generating material, such as a superabsorbent, said material, as it expands to absorb liquid, it does not form a barrier through which a liquid movement and fluid movement cannot generally pass. In this way, each opening in the absorbent layer provides a fluid passage between the transmission layer directly to the wound-facing filter surface and then onward into the port.

A gas-impermeable, but moisture vapor-permeable cover layer 140 extends through the thickness of the wound dressing. The cover layer, which can be, for example, a polyurethane film (e.g. Elastollan SP9109) with a pressure-sensitive adhesive on one side, is gas-tight and therefore this layer acts to cover the wound and sealing a wound cavity over which the wound dressing is placed. In this way, an effective chamber is created between the cover layer and the wound area where a negative pressure can be established. Cover layer 140 is sealed to wound contact layer 102 in an edge region 200 around the circumference of the dressing, thus ensuring that no air enters through the edge area, for example, by adhesives or embossing techniques. soldier. Cover layer 140 protects the wound from external bacterial contamination (bacterial barrier) and allows fluid from wound exudates to transfer through the layer and evaporate from the outer surface of the film. Cover layer 140

ES 2 571 332 T3 typically comprises two layers; a polyurethane film and a spread adhesive design on the film. Polyurethane film is permeable to moisture vapor and can be made from a material that, when wet, has a higher water transmission rate.

The absorbent layer 110 may have a larger surface area than the transmission layer 105, as illustrated in Figure 1, so that the absorbent layer overlaps the edges of the transmission layer 105, thus ensuring that the layer of transmission does not come into contact with the cover layer 140. This provides an outer channel 115 of the absorbent layer 110, that is, it is in direct contact with the wound contact layer 102, which aids in faster absorption of exudates into the absorbent layer. Furthermore, this outer channel 115 ensures that no liquid is puddled around the circumference of the wound cavity, which would otherwise infiltrate around the perimeter of the dressing, leading to the formation of leaks.

To ensure that the air channel remains open when vacuum is applied to the wound cavity, the transmission layer 105 must be strong enough and unable to sag in order to resist the force applied by the pressure difference. However, if this layer comes into contact with the relatively delicate cover layer 140, it can cause the formation of pin-point openings in the cover layer 140, which allow air to leak into the wound cavity. This can be a specific problem when using an exchangeable type polyurethane film, which weakens on wetting. The absorbent layer 110 is generally formed of a relatively soft and non-abrasive material compared to the material of the transmission layer 105 and, therefore, does not cause the formation of pin holes in the cover layer. Therefore, by providing an absorbent layer 110 which has a larger surface area than the transmission layer 105 and which overlaps the edges of the transmission layer 105, the transmission layer and the cover layer are prevented from coming into contact. , thus avoiding the formation of pinpoint openings in the cover layer 140.

The absorbent layer 110 is placed in contact with the cover layer 140. As the absorbent layer absorbs the exudate from the wound, the exudate is drawn into the cover layer 140, bringing the water component of the exudate in contact with the wound. moisture vapor permeable cover layer. This water component is drawn into the cover layer itself and then evaporates from the top surface of the dressing. In this way, the water content of the wound exudate can perspire through the dressing, decreasing the volume of the remaining wound exudate that will be absorbed by the absorbent layer 110, and increasing the time until the dressing fills and must be changed. This perspiration process occurs even when negative pressure has been applied to the wound cavity, and it has been found that the pressure difference across the covering layer when negative pressure is applied to the wound cavity has negligible impact. in the rate of moisture vapor transmission through the cover layer.

A hole 145 is provided in the cover sheet 140 to allow the application of negative pressure to the dressing 100. A suction port 150 in the top of the cover sheet 140 is sealed over the hole 145, which communicates the pressure. negative through hole 145. A length of tubing 220 can be attached to a first end of suction port 150 and, at a second end, to a pump unit (not shown) to allow fluids to be pumped out of the dressing. The port can be adhered and sealed to the cover sheet 140 using an adhesive such as acrylic, cyanoacrylate, epoxy, UV curing, or hot melt adhesive. Port 150 is made of a soft polymer, such as polyethylene, polyvinyl chloride, silicone, or polyurethane that has a hardness of 30 to 90 on the Shore A scale.

An opening is provided in absorbent layer 110 below hole 145 so that the hole connects directly with transmission layer 105. This allows negative pressure applied to port 150 to be transmitted to transmission layer 105 without passing through. through absorbent layer 110. This ensures that negative pressure applied to the wound area is not inhibited by the absorbent layer as it absorbs wound exudates. In other embodiments, no opening can be provided in absorbent layer 110 or, alternatively, a plurality of openings can be provided underlying hole 145.

As shown in Figure 1, one embodiment of wound dressing 100 comprises an opening in absorbent layer 100 located below port 150. In practice, for example when negative pressure is applied to the dressing 100, a portion of the port 150 facing the wound can then come into contact with the transmission layer 105, which can then contribute to the transmission of the negative pressure to the area. wound even when absorbent layer 110 is filled with wound fluids. Some embodiments may have cover layer 140 at least partially adhered to transmission layer 105. In some embodiments, the opening is at least 1-2 mm wider than the diameter of port 150, or hole 145.

A filter element 130 that is liquid impermeable, but gas permeable, is provided to act as a barrier against liquids, and to ensure that no liquid escapes from the wound dressing. The filter element can also function as a bacterial barrier. Typically the pore size is 0.2 pm. Suitable materials for the filter material of the filter element 130 include Gore ™ 0.2 micron expanded polytetrafluoroethylene (PTFE) from the MMT range, PALL Versapore ™ 200R, and Donaldson ™ TX6628. Larger pore sizes can also be used, but these may require a secondary filter layer to ensure full containment of bacterial load. Because the wound fluid contains lipids, it is preferable, although not essential, that an oleophobic filter membrane, for example 1.0 micron MMT-332, is used rather than

ES 2 571 332 T3

0.2 micron MMT-323. This prevents lipids from blocking the hydrophobic filter. The filter element may be attached or sealed to a port and / or cover sheet 140 over the hole 145. For example, the filter element 130 may be molded within the port 150, or it may be adhered to both the top of the cover layer 140 as well as to the bottom of the port 150 using an adhesive, such as a UV light curing adhesive.

It will be understood that other types of materials may be used for the filter element 130. More generally, a microporous membrane can be used, which is a flat, thin sheet of polymeric material, containing billions of microscopic pores. Depending on the selected membrane, the size of these pores can range from 0.01 to more than 10 microns. Microporous membranes are also available in both their hydrophilic (water filtered) and hydrophobic (water repellent) forms. In some embodiments of the invention, filter element 130 comprises a support layer and an acrylic copolymer membrane formed on the support layer. Successfully, wound dressing 100 according to certain embodiments of the present invention utilizes microporous hydrophobic membranes (MHM). Various polymers can be used to form the MHMs. For example, PTFE, polypropylene, PVDF, and acrylic copolymer. All of these optional polymers can be treated to obtain specific surface characteristics that can be both hydrophobic and oleophobic. As such, such polymers will repel liquids with low surface tensions, such as multivitamin infusions, lipids, surfactants, oils, and organic solvents.

MHMs block fluids while allowing air to flow through the membranes. They are also highly efficient air filters that remove potentially infectious aerosols and particles. A single piece of MHM is well known as an option to replace mechanical valves or breathers. The incorporation of MHM can therefore reduce product assembly costs, improving profitability and cost-effectiveness for a patient.

Filter element 130 may also include an odor absorbing material, for example activated carbon, carbon fiber cloth, or Vitec Carbotec-RT Q2003073 foam or the like. For example, an odor absorbing material can form a layer of filter element 130 or it can be sandwiched between the microporous hydrophobic membranes within the filter element.

Thus, filter element 130 allows gas to be expelled through orifice 145. However, the dressing contains liquids, particles, and pathogens.

In particular, for embodiments with a single port 150 and through hole, it may be preferable that the port 150 and the through hole are located in an off-centered position, as illustrated in Figures 1 and 2. Such a location may allow dressing 100 is placed on a patient such that port 150 is elevated relative to the remainder of dressing 100. In such a position, port 150 and filter 130 are less likely to come into contact with wound fluids that could prematurely clog filter 130, so as to prevent transmission of negative pressure to the wound area.

Figure 11 shows a plan view of a suction port 150 according to some embodiments of the invention. The suction port comprises a sealing surface 152 for sealing the port to a wound dressing, a connector portion 154 for connecting the suction port 150 to a source of negative pressure, and a hemispherical body portion 156 disposed between the surface. seal 152 and connector portion 154. Sealing surface 152 comprises a flange that provides a substantially flat surface to provide an effective seal when port 150 is sealed to cover layer 140. Connector portion 154 is arranged to engage the external source of negative pressure by means of a tube length 220.

According to certain embodiments, the filter element 130 forms part of the bacterial barrier over the wound area and, therefore, it is important that an effective seal is formed and maintained around the filter element. However, it has been determined that a seal formed by adhering filter element 130 to cover layer 140 is not reliable enough. This is a particular problem when using a moisture vapor permeable cover layer, as the water vapor that transpires from the cover layer 140 can affect the adhesive, resulting in a fracture in the seal between the sealing element. filter and cover layer. Therefore, according to some embodiments of the invention, an alternative arrangement is employed to seal the filter element 130 to prevent liquid from entering the connector portion 154.

Figure 12 illustrates a cross section of the suction port 150 of Figure 11 according to some embodiments of the invention, and the line AA in Figure 11 indicates the location of the cross section. In the suction port of Figure 12, the suction port 150 further comprises an element filter 130 disposed within the body portion 156 of the suction port 150. A seal between the suction port 150 and the filter element 130 is achieved by molding the filter element within the body portion of the suction port 150.

Figure 13 illustrates a cross section of the suction port 150 of Figure 11 according to certain embodiments of the invention. In the suction port of Figure 13, the filter element 130 is sealed to the sealing surface 152 of the suction port 150. The filter element can be sealed to the sealing surface by means of an adhesive or by welding the filter element. to the sealing surface.

ES 2 571 332 T3

By providing filter element 130 as part of suction port 150, as illustrated in Figures 12 and 13, problems associated with adhesion of filter element to cover layer 140 are avoided, which allows reliable sealing can be provided. Furthermore, by providing a sub-assembly having a filter element 130 included as part of the suction port 150, it is possible to manufacture the wound dressing 100 in a simpler and more efficient manner.

Although the suction port 150 has been described in the context of the wound dressing 100 of Figure 1, it will be understood that the embodiments of Figures 12 and 13 can be applied to any wound dressing to apply negative pressure to a wound. , wherein wound exudate removed from said wound is retained within the dressing. According to some embodiments of the invention, the suction port 150 may be made of a transparent material so that the user can visually check the entry of wound exudate into the suction port.

In practice, the wound dressing 100 is sealed over the wound area to form a wound cavity. A pump unit (illustrated in Figure 17 and described in greater detail below) applies negative pressure to a connection port 154 of port 150 that is transmitted through orifice 145 to transmission layer 105. Fluid moves into the hole through the wound dressing from a wound area below the wound contact layer 102. Fluid moves into the orifice through transmission layer 105. As fluid moves through transmission layer 105, wound exudate is absorbed by absorbent layer 110.

Referring to Figure 2 illustrating a wound dressing 100 according to one embodiment of the present invention, the top surface of cover layer 140 can be seen extending outward from the center of the dressing to an edge region 200 that surrounds a central raised region 201, superimposed on transmission layer 105 and absorbent layer 110. As indicated in Figure 2, the general shape of the wound dressing is rectangular with rounded corner regions 202. It will be appreciated that wound dressings according to other embodiments of the present invention may take different shapes such as dressings. square, circular or elliptical, or the like.

Wound dressing 100 can be sized as required based on the size and type of wound in which it will be used. In some embodiments, the wound dressing 100 may measure between 20 and 40 cm on its long axis, and between 10 and 25 cm on its short axis. For example, dressings can be provided in the sizes 10 x 20 cm, 10 x 30 cm, 10 x 40 cm, 15 x 20 cm, and 15 x 30 cm. In some embodiments, wound dressing 100 may be a square-shaped dressing with sides measuring between 15 and 25 cm (eg, 15 x 15 cm, 20 x 20 cm, and 25 x 25 cm). The absorbent layer 110 may have a smaller surface area than the entire dressing, and in some embodiments it may have both a length and a width about 3 to 10 cm shorter, more preferably about 5 cm shorter, than that of the entire dressing 100. . In some rectangular-shaped embodiments, absorbent layer 110 can measure between 15 and 35 cm on its long axis, and between 5 and 10 cm on its short axis. For example, absorbent layers can be provided in sizes 5.6 x 15 cm (for 10 x 20 cm dressings), 5.6 x 25 cm (for 10 x 30 cm dressings), 5.6 x 35 cm (for 10 x 40 cm dressings), 10 x 15 cm (for 15 x 20 cm dressings), and 10 x 25 cm (for 15 x 30 cm dressings). In some square-shaped embodiments, the absorbent layer 110 may have sides that are between 10 and 20 cm in length (eg, 10 x 10 cm for a 15 x 15 cm dressing, 15 x 15 cm for a 6-inch dressing). 20 x 20 cm, or 20 x 20 cm for a 25 x 25 cm dressing). The transmission layer 105 is preferably smaller than the absorbent layer and, in some embodiments, may have both a length and a width both of about 0.5 to 2 cm shorter, more preferably about 1 cm shorter. than those of the absorbent layer. In some rectangular-shaped embodiments, the transmission layer may measure between 14 and 34 cm on its long axis, and between 3 and 5 cm on its short axis. For example, transmission layers can be provided in sizes 4.6 x 14 cm (for 10 x 20 cm dressings), 4.6 x 24 cm (for 10 x 30 cm dressings), 4 x 34 cm ( for 10 x 40 cm dressings), 9 x 14 cm (for 15 x 20 cm dressings), and 9 x 24 cm (for 15 x 30 cm dressings). In some square-shaped embodiments, the transmission layer may have sides that are between 9 and 19 cm in length (e.g., 9 x 9 cm for a 15 x 15 cm dressing, 14 x 14 cm for a 6-inch dressing). 20 x 20 cm, or 19 x 19 cm for a 25 x 25 cm dressing).

It will be understood that according to embodiments of the present invention the wound contact layer is optional. If used, this layer is porous to water and faces an underlying wound area. A transmission layer 105 such as an open cell foam, or a knitted or woven spacer fabric is used to distribute the gas and fluid removal so that all areas of a wound are subjected to equal pressure. The cover layer together with the filter layer forms a substantially tight seal over the wound. Therefore, when negative pressure is applied to port 150, the negative pressure is transmitted to the wound cavity below the covering layer. Therefore, this negative pressure is experienced in the area of ​​the target wound. Fluid, including air and wound exudate, is drawn into the wound contact layer and transmission layer 105. Wound exudate drawn through the lower layers of the wound dressing is dissipated and absorbed into absorbent layer 110 where it is collected and stored. Air and moisture vapor are drawn up through the wound dressing, through the filter layer, and out of the dressing through the suction port. A portion of the water content of the wound exudate is drawn through the absorbent layer and into the cover layer 140 and then evaporates from the surface of the dressing.

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As discussed above, when negative pressure is applied to a sealed wound dressing over a wound area, fluids, including wound exudate, are drawn out of the wound area and through transmission layer 105 toward hole 145. The wound exudate is then drawn into absorbent layer 110 where it is absorbed. However, some of the exudate from the wound may not be absorbed and may move into hole 145. The filter element 130 provides a barrier that prevents any liquid from the wound exudate from entering the connection portion 154 of the suction port 150. Therefore, the wound exudate that was not absorbed can collect under the filter element. 130. If a sufficient amount of wound exudate is collected on the filter element, a layer of liquid will form on the surface of the filter element 130 and the filter element will become blocked, as the liquid cannot pass through the filter element. filter 130 and the liquid layer will prevent gases from reaching the filter element. Once the filter element is blocked, the negative pressure can no longer be transmitted to the wound area, and the wound dressing must be changed to a new one even if the full capacity of the absorbent layer has not been reached.

In a preferred embodiment, port 150, along with any opening 146 in absorbent layer 110 located below it, is generally aligned with the longitudinal median axis AA illustrated in Figure 2. Preferably, port 150 and any opening 146 are located. closer to one end of the dressing, as opposed to a central position. In some embodiments, the port may be located in a corner of the dressing 100. For example, in some rectangular embodiments, port 150 may be located 4 to 6 cm from the edge of the dressing, with opening 146 located 2 to 3 cm from the edge of the absorbent layer. In some square embodiments, port 150 may be located 5 to 8 cm from the corner of the dressing, with opening 146 located 3 to 5 cm from the corner of the absorbent layer.

Some orientations of the wound dressing may increase the chances that the filter element 130 will become blocked in this manner, as the movement of wound exudate through the transmission layer may be aided by the effect of gravity. Therefore, if due to the orientation of the wound area and the wound dressing, gravity acts to increase the speed at which the wound exudate moves into the hole 145, the filter can be blocked with wound exudate with faster. Therefore, the wound dressing will need to be changed more frequently and before the absorbent capacity of the absorbent layer 110 is achieved.

To prevent wound exudate moving into hole 145 from prematurely blocking wound dressing 100, some embodiments of the invention include at least one element configured to reduce the speed at which wound exudate moves into the hole. 145. That at least one element can increase the amount of exudate that is absorbed into the absorbent layer before reaching hole 145 and / or can force exudate from the wound to follow a longer path through the dressing before reaching hole 145 , thus increasing the time for the wound dressing to lock.

Figure 3 shows a plan view of a wound dressing that includes deflector elements that reduce the rate at which wound exudate moves into the hole, in accordance with one embodiment of the invention. The wound dressing illustrated in Figure 3 is similar to those shown in Figures 1 and 2, but includes a number of deflector elements 310 disposed along the central raised region 201. Deflector elements 310 form barriers in the central region of the dressing, which prevent wound exudate from moving into the hole.

Embodiments of deflectors that can be used in the wound dressing described herein are preferably at least partially flexible, to allow the wound dressing to flex and conform to the patient's skin surrounding the wound area. When present on the wound dressing, the deflector elements are preferably constructed to at least partially prevent liquid from flowing directly into the port or orifice of the wound dressing and its associated filter, if applicable. Thus, the deflector elements increase the distance that liquids may require to reach the port, which can aid in the absorption of these fluids into the absorbent or superabsorbent material of the wound dressing.

According to some embodiments of the invention, the deflector element may comprise a sealing region in which absorbent layer 110 and transmission layer 105 do not exist and in which cover layer 140 is sealed to the wound contact layer. 101. Therefore, the deflector element presents a barrier to the movement of wound exudate, which must therefore follow a path that avoids the deflector element. Therefore, the time it takes for wound exudate to reach the hole is increased.

In some embodiments, the deflector elements may be an insert of a substantially non-porous material, for example, a closed cell polyethylene foam, located within the dressing. In some cases, it may be preferable to place said inserted baffle element in a sealing region where there is no one or more of the absorbent layers 110 and / or transmission layer 105. A sealant, for example a viscous curing sealant, such as a silicone sealant, can be applied or injected into a thin strip to form a baffle element that is substantially impermeable to liquid. Said deflector element can be applied or injected in a region of the transmission layer 105 and / or absorbent layer 110, or also in a sealing region where there is no absorbent layer 110 and / or a transmission layer 105.

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Figure 6 illustrates a wound dressing including a deflector member according to one embodiment of the invention. A single deflector element 610 provides a cup-shaped barrier between the bulk of the absorbent layer 110 and the hole 145. Therefore, wound exudate that is initially drawn from the wound area within the region defined by deflector element 610, must follow a path around the outside of the cup-shaped barrier to reach hole 145. As can be seen, deflector element 610 reduces the effect of gravity by reducing the time it takes for wound exudate to move toward hole 145, since for most wound dressing orientations at least a portion of the path made by the exudate from the wound will be made against the force of gravity.

The embodiments of Figures 3 and 6 have been described with respect to a wound dressing having a structure as shown in Figure 1. However, it will be understood that the deflector elements could equally be applied to a wound dressing that had no transmission layer 105.

Figure 4 shows a plan view of a wound dressing including at least one element according to one embodiment of the invention in which a number of deflector elements 410 are provided which extend along the width of the central region 201 of the wound dressing, with additional deflector elements 412 formed in a semi-circular path around hole 145.

Figure 5 illustrates the configuration of deflector elements 410 according to some embodiments of the invention. The deflector element comprises a channel of absorbent material 510 underlying the transmission layer 105. A channel is placed in the absorbent layer 110 over the deflector element 410 so that the transmission layer is in contact with the cover layer 140 in the region deflector element 410. Therefore, wound exudate that moves along a lower surface of transmission layer 105, and therefore has not been drawn into absorbent layer 110, will come into contact with the absorbent material channel. 510 and will be absorbed by it.

Alternatively, or additionally, the deflector elements may comprise one or more channels provided in the surface of the transmission layer 105 underlying or abutting the absorbent layer 110. In practice, when negative pressure is applied to the wound dressing, the absorbent layer 110 will move into the channel. The channel in the transmission layer can have a depth substantially equal to the depth of the transmission layer, or it can have less depth than the depth of the transmission layer. Channel dimensions can be chosen to ensure that absorbent layer 110 fills the channel when negative pressure is applied to the wound dressing. According to some embodiments, the channel in the transmission layer comprises a channel of absorbent material in the transmission layer 105.

The deflector elements can take various shapes and patterns, for example, Figures 14A to 14L illustrate wound dressings exhibiting a number of different exemplary configurations of the deflector elements. Figure 14A illustrates a linear deflector element in a vertical configuration aligned in the direction of the port or orifice. Figure 14B illustrates an X-shaped deflector element. Figures 14C-E illustrate wound dressing embodiments with multiple deflector elements, generally aligned diagonally, horizontally, or vertically.

Figure 14F illustrates deflector elements arranged in a six-arm star configuration, with a center portion remaining open. Figure 14G illustrates a W-shaped deflector element on the wound dressing in a position distal to the port or hole. In Figure 14H, X-shaped deflector elements arranged in a 3 x 3 formation are provided in the wound dressing, although it will be understood that more or fewer X-shaped deflector elements can be used. Figure 14I shows a embodiment with a plurality of rectangular deflector elements, and in which one or more deflector elements are located below the port in the wound dressing. Figures 14J-K illustrate wound dressing embodiments with longer horizontal and diagonal deflectors. Figure 14L presents rectangular deflector elements in this embodiment of a wound dressing, in which the deflector elements are of different sizes.

According to some embodiments of the invention, the at least one element comprises a variety of vias, or depressions, in the transmission layer 105. Figure 15 illustrates a transmission layer 105 that is perforated with diamond-shaped vias 210. The tracks 210 are arranged so that there is no linear path through the track pattern that does not intersect with one or more of the tracks 210.

When negative pressure is applied to the wound dressing, the absorbent layer 110 moves toward the pathways 210, increasing the area of ​​the absorbent layer that comes into contact with wound exudate that is drawn through the transmission layer 105. Alternatively, the pathways 210 can be filled with additional absorbent material to absorb wound exudate that is drawn through the transmission layer 105. The pathways may extend through the depth of the transmission layer 105, or they may extend through only a portion of the transmission layer.

Wound exudate moving through the transmission layer 105 under the influence of gravity will fall through the transmission layer in a substantially linear fashion. Any of these linear trajectories is

ES 2 571 332 T3 will intersect, at some point, with one of the pathways 210, and therefore, the exudate will come into contact with the absorbent material within the pathways 210. The wound exudate that comes into contact with the material The absorbent will be absorbed, stopping the flow of wound exudate through transmission layer 105, and decreasing the amount of unabsorbed wound exudate that would otherwise pool around the hole. It will be appreciated that the shape of the tracks is not limited to that of diamond and that any other design can be used. Preferably, the paths will be arranged to ensure that all linear paths through the transmission layer 105 intersect with at least one path. It is possible to choose the design of the pathways in order to minimize the distance that the wound exudate is able to travel through the transmission layer before encountering a pathway and being absorbed.

Figure 7 illustrates a wound dressing according to some embodiments of the invention in which at least one element comprises an air channel 710 connecting the central region 201 of the wound dressing with the hole 145. In the embodiment of Figure 7, the air channel 710 extends from an edge region of the transmission layer 105 and connects the transmission layer with the hole 145.

In practice, wound exudate is moved into port 145 by applying negative pressure to suction port 150. However, air channel 710 has a relatively long meandering path that wound exudate will travel sooner. reach hole 145. This long trajectory increases the time during which negative pressure can be applied to the dressing before wound exudate travels the distance between the transmission layer and the orifice and blocks the filter element 130, thus increasing the time during which the dressing remains in use before it needs to be changed.

Figure 8 illustrates a wound dressing according to an embodiment of the invention in which at least one element comprises air channels 810 and 812 that connect central region 201 of the wound dressing with port 145. Channels 810 and 812 are engaged. to the transmission layer at corners substantially opposite the central region 201.

The wound dressing shown in Figure 8 reduces the effect of gravity on the time it takes for the hole to block. If the wound dressing is oriented so that the wound exudate moves under the effects of gravity towards the edge region of the transmission layer connected to the air channel 810, the effect of gravity will be to move the exudate away from the wound of the edge region of the transmission layer coupled to the air channel 812, and vice versa. Therefore, the embodiment of Figure 8 offers alternative air channels for coupling negative pressure to the transmission layer, so that if one air channel were to become blocked, a remaining air channel should remain open and be able to transmitting the negative pressure to the transmission layer 105, thus increasing the time until negative pressure can no longer be applied to the wound dressing and the dressing needs to be changed.

Some additional embodiments of the invention may comprise a greater number of air channels connecting the transmission layer 105 with the hole.

According to some embodiments of the invention, two or more holes are provided in the cover layer 140 to apply the negative pressure to the wound dressing. The two or more holes may be distributed through cover layer 140 such that if wound exudate were to obstruct one of the holes because the wound dressing is in a particular orientation, at least one remaining hole would be expected to remain. unlocked. Each hole has fluid communication with a wound chamber defined by the wound dressing and is therefore capable of transmitting negative pressure to the wound area.

Figure 9 illustrates a wound dressing according to a further embodiment of the invention. The wound dressing of Figure 9 is similar to that of Figure 1, but includes two holes 145 and 845 provided in the cover layer 140. A fluid transmission passage connects the two holes so that a negative pressure applied to one from the orifices is transmitted to the remaining orifice via the fluid transmission passage. The holes 145,845 are located in opposite corner regions of the cover layer 140. The fluid transmission passage is formed using a flexible molding 910 on the upper surface of the cover layer 140. It will be appreciated that it is possible to form the flexible molding by other appropriate means, for example, a transmission strip or open porous foam layer in the cover layer 140 between the holes 145 and 845 and an additional film welded or adhered on the strip, thus sealing it to the cover layer and forming a passage through the foam. A conduit can then be attached to the sealing film in a known manner in order to be able to apply negative pressure.

In practice, the wound dressing having two holes is sealed over a wound area to form a wound cavity, and an external source of negative pressure is applied to one of the holes 145, 845, and the negative pressure will be transmitted to the remaining orifice via the fluid transmission passage. Therefore, the negative pressure is transmitted through the two holes 145,845 to the transmission layer 105 and hence to the wound area. If one of the ports 145, 845 becomes clogged due to accumulated wound exudate in the port under the effects of gravity, the remaining port must remain clear, allowing negative pressure to continue to be transmitted to the wound area. According to some embodiments, the transmission layer 105 can be bypassed, and the two holes will transmit the negative pressure to the wound area via the absorption layer 110.

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Figure 10 illustrates a side view of the fluid transmission passage of the embodiment of Figure 9. The trim 910 is sealed to the top surface of the cover layer 140, and covers the holes 145 and 845. In each hole are offered Gas-permeable and liquid-impermeable filter elements 130. Trim 910 is coupled to an external source of negative pressure via tube element 220.

According to some embodiments, a single filter element can be used that extends down the length of the fluid transmission passage and the two ports. While the above embodiment has been described with two ports, it will be understood that more than two ports can be used, the fluid transmission path allowing negative pressure to be transmitted between the ports.

Figure 16 illustrates an alternative arrangement in which a single elongated hole 350 is provided in cover layer 140. First and second ends 355, 356 of hole 350 are located in opposite corner regions of cover layer 140. A Flexible trim 360 is sealed around hole 350 and allows negative pressure to be transmitted through cover layer 140 along the length of hole 350. Flexible molding 360 may be formed by any appropriate means, as described above with reference to flexible molding 910.

In practice, the wound dressing is sealed over a wound area to form a wound cavity and an external source of negative pressure is applied to the hole. If, due to the orientation of the wound dressing, wound exudate moves under the effects of gravity to accumulate around one end 355 of hole 350, a portion of hole 350 near end 355 will become obstructed. However, a portion of the orifice near the remaining end 356 should remain clear, allowing continued application of negative pressure to the wound area.

Even as additional options, the dressing may contain antimicrobials, for example nanocrystalline silver agents in the wound contact layer and / or silver sulfadiazine in the absorbent layer. These can be used together or separately. These agents kill, respectively, microorganisms in the wound and microorganisms in the absorption matrix. Even as an additional option, other active compounds can be included, for example pain relievers, such as ibuprofen. Furthermore, agents that optimize cell activity, such as growth factors or that inhibit enzymes, such as matrix metalloproteinase (MMP) inhibitors, or zinc chelating agents, can also be used. Even an additional option are odor-absorbing elements, such as activated carbon, cyclodextrin, zeolite or the like, which can be included in the absorbent layer or even as an additional layer on top of the filter layer.

It should be noted that in practice the dressing can be used upside down, at an angle or in an upright position. Therefore, references to upper and lower are included for illustrative purposes only.

Figure 17 illustrates an embodiment of an PNT wound treatment comprising a wound dressing 100 in combination with a pump 800. Here, the dressing 100 can be located over a wound as previously described, and a conduit 220 can then be connected to port 150, although in some embodiments dressing 100 may be provided with at least a portion of conduit 220 pre-attached to port 150. Preferably, dressing 100 is provided as a single article with all elements of the wound dressing (including port 150) preset and integrated into a single unit. Wound dressing 100 may then be connected, via conduit 220, to a negative pressure source such as pump 800. Preferably, pump 800 is miniaturized and portable, although conventional larger pumps can be used with dressing 100. size. In some embodiments, pump 800 may be attached or mounted on or adjacent to dressing 100. A connector 221 may also be provided to allow conduit 220 leading to wound dressing 100 to be disconnected from the pump, which may be useful, for example, during dressing changes.

Figures 18 AD illustrate the use of one embodiment of an PNT wound management system being used to treat a wound area in a patient. Figure 18A shows a wound area 190 that is being sanitized and prepared for treatment. At this point, it is preferable that the healthy skin surrounding the wound area 190 is clean and that excess hair is removed or shaved off. The wound area 190 can also be flushed with a sterile saline solution if necessary. Optionally, a skin protector can be applied to the skin surrounding the wound area 190. If necessary, a wound filler material, such as foam or gauze, can be placed in the wound area 190. This may be preferable if the wound area 190 is a deeper wound.

After the skin surrounding the wound area 190 has dried, and referring now to Figure 18B, the wound dressing 100 may be positioned and positioned over the wound area 190. Preferably, the wound dressing 100 is in place. with wound contact layer 102 on and / or in contact with wound area 190. In some embodiments, an adhesive layer is provided on the lower surface 101 of the wound contact layer 102, which in some cases may be protected by an optional release layer that will be removed prior to placing the wound dressing 100 over the wound. wound area 190. Preferably, dressing 100 is positioned such that port 150 is in an elevated position relative to the rest of dressing 100 to prevent fluid from pooling around the port. In some embodiments, the dressing 100 is

ES 2 571 332 T3 positioned so that port 150 is not directly superimposed on the wound and is flush with or higher than the wound. To ensure a proper seal for the PNT, it is preferred that the edges of the dressing 100 are smoothed to avoid wrinkles or creases.

Referring now to Figure 18C, dressing 100 is connected to pump 800. Pump 800 is configured to apply negative pressure to the wound area via dressing 100, and typically via conduit. In some embodiments, and as described above in Figure 28, a connector may be used to join the dressing conduit 100 to the pump 800. When applying negative pressure with the pump 800, it is possible that in some embodiments the dressing 100 may partially sag and exhibit a wrinkled appearance as a result of the complete or partial evacuation of the air housed under the dressing 100. In some embodiments, the pump 800 may be configured to detect if the dressing 100 is leaking, such as at the interface between the dressing 100 and the skin surrounding the wound area 190. If a leak is detected, it is preferable to repair it before continuing with the treatment.

Referring to Figure 18D, additional fixation strips 195 may also be attached around the edges of the dressing 100. Such fixation strips 195 may be advantageous in some situations to provide an additional seal on the patient's skin surrounding the area of ​​dressing. wound 190. For example, fixation strips 195 can provide additional sealing for when a patient is more mobile. In some cases, the fixation strips 195 may be used prior to activating the pump 800, particularly if the dressing 100 is located in a difficult to access or curved area.

Treatment of wound area 190 preferably continues until the wound has reached a desired level of healing. In some embodiments, it may be desirable to change the dressing 100 after some time has passed, or if the dressing is filled with wound fluids. During such changes, the pump 800 can be maintained, changing only the dressing 100.

Throughout the description and claims of this specification, the words comprise and contain and their variants, for example, comprising and comprises, are meant to include, but are not limited to, and are not intended to exclude (and not excluded) other residues, additives, components, integers or stages.

Throughout the description and claims of this specification, the singular comprises the plural unless the context requires otherwise. In particular, when using the indefinite article, it should be understood that the specification contemplates both plurality and singularity, unless the context requires otherwise.

Particularities, integers, characteristics, compounds, moieties or chemical groups described in conjunction with a particular aspect, embodiment or example of the invention should be understood as applicable to any other aspect, embodiment or example described herein unless incompatible with the invention. herself.