Dressing for use in the negative pressure therapy of wounds, negative pressure wound therapy kit, and negative pressure wound therapy system

Abstract

The invention relates to a dressing (16) for use in the negative pressure therapy of wounds, having: a wound contact layer (28); an air-impermeable top layer (34), wherein a receiving space (36) is formed between the top layer and the wound contact layer, wherein the wound contact layer is designed such that it is liquid-permeable and draws wound exudate from the wound into the receiving space, and wherein a connection opening (26) is formed in the top layer; and at least one distribution layer (50) arranged in the receiving space, wherein the distribution layer extends in two surface directions (X, Y) and is designed to distribute wound exudate in the surface directions. According to the invention, the distribution layer is formed by a flat material web portion (52), a first side (56) of the flat material web portion is designed as a structure defined by elevations (60) that are formed integrally with a plane (54) of the flat material web portion, a terminal through-opening (64) is formed in at least some of the elevations, and a cohesive intermediate space (66) is formed between the elevations.

Description

[0001] Title : Wound dressing for use in

[0002] Negative pressure wound therapy, negative pressure wound therapy kit and negative pressure wound therapy system

[0003] Description

[0004] The present invention relates to a wound dressing for use in negative pressure therapy of wounds. The present invention also relates to a negative pressure wound therapy kit comprising such a wound dressing. Furthermore, the present invention relates to a negative pressure wound therapy system comprising a negative pressure source and such a negative pressure wound therapy kit. Negative pressure therapy of wounds, also called NPWT = Negative Pressure Wound Therapy, is an innovative method for wound treatment with a wide range of indications. These include, for example, acute skin or soft tissue defects, impaired wound healing, chronic wounds, etc. The aim of negative pressure therapy is to stimulate the growth of granulation tissue and promote the healing process. During negative pressure therapy, a negative pressure is created in the area of ​​a wound, whereby wound exudate can be effectively drained from the wound.

[0005] Wound dressings used in negative pressure therapy typically comprise a wound contact layer for application to the wound base and an air-impermeable cover layer for sealing the wound airtight. A receiving space is formed between the wound contact layer and the cover layer. The wound contact layer is designed to be liquid-permeable to drain wound exudate from the wound into the receiving space. The cover layer comprises a connection opening for the vacuum-tight fluidic connection of the receiving space to a vacuum source. When the wound dressing is applied to a wound as intended and the vacuum source is fluidly connected to the connection opening in a vacuum-tight fluidic connection, the vacuum source can create a negative pressure in the wound space and the receiving space.In known wound dressings, at least one distribution layer is generally arranged in the receiving space. This distribution layer extends in two surface directions and is designed to distribute wound exudate in the surface directions. Distribution in the surface directions is also referred to below as lateral distribution. The lateral distribution of the wound exudate prevents accumulation of wound exudate and any associated blockages of components of the wound dressing. Furthermore, the distribution layer also promotes a lateral distribution of the negative pressure in the wound space.

[0006] A generic wound dressing is known, for example, from patents EP 3 287 106 B1 and EP 2 879 636 B1. These patents propose various materials for the distribution layer, such as an open-cell foam, a spacer fabric, or a nonwoven fabric. While such materials meet the basic requirements for a distribution layer, the use of these materials is relatively expensive. This was deliberately accepted in previously known wound dressings.

[0007] The object of the invention is to provide a wound dressing for negative pressure therapy of wounds which ensures an effective lateral distribution of wound exudate in the receiving space using cost-effective means.

[0008] This object is achieved according to the invention by a wound dressing according to claim 1, by a negative pressure wound therapy kit according to claim 22, and by a negative pressure wound therapy system according to claim 23. The subclaims and the description indicate advantageous variants and embodiments.

[0009] According to the invention, a wound dressing is provided for use in negative pressure wound therapy. The wound dressing comprises a wound contact layer for application to the base of a wound. The wound contact layer comprises a smooth first side and a smooth second side facing away from the first side. Furthermore, the wound dressing according to the invention comprises an air-impermeable cover layer for hermetically sealing the wound.

[0010] A receiving space is formed between the cover layer and the wound contact layer. The wound contact layer is designed to be liquid-permeable to drain wound exudate from the wound into the receiving space. The wound contact layer is preferably perforated so that the wound exudate can pass through the wound contact layer through perforations or through openings formed in the wound contact layer. However, the wound contact layer can also be intrinsically liquid-permeable. A connection opening for the vacuum-tight fluidic connection of the receiving space to a vacuum source is formed in the cover layer. The wound dressing according to the invention further comprises at least one distribution layer arranged in the receiving space. The distribution layer extends in two surface directions and is designed to distribute wound exudate in the surface directions.It is now provided that the distribution layer is formed by a flat material web section, that a first side of the flat material web section is structured by elevations formed in one piece with a plane of the flat material web section, that an end-side through-opening is formed in at least some of the elevations, and that a continuous intermediate space is formed between the elevations, so that wound exudate can be distributed in the intermediate space in the surface directions.

[0011] It has surprisingly been found that a flat material web section designed as above is, in view of its properties, particularly suitable as a distribution layer or as a component of a distribution layer. Wound exudate drained into the receiving space can be transported through the flat material web section through the end through-openings orthogonal to the surface directions. In the intermediate space or through the intermediate space, wound exudate can be distributed in the surface directions, in particular along the first side of the flat material web section. A flat material web section designed as above is available at low cost. This results in particular from the fact that suitable elevations can be formed in a flat material web or a flat material web section with little time and effort.The use of a flat material web section in a distribution layer or as a distribution layer also has the advantage of producing a wound dressing that ensures high patient comfort. This is particularly due to the fact that a wound dressing with a low overall height can be achieved.

[0012] A flat material web section is a section of a flat material web. For example, the flat material web section is cut out of a flat material web. Preferably, the elevations are already formed in the flat material web. However, the elevations can also be formed in the flat material web section. In particular, the flat material web is a plastic film web, so the flat material web section is formed as a plastic film.

[0013] The flat material web section on the first side preferably has an elevation density of at least 50 elevations per cm2, preferably an elevation density of at least 100 elevations per cm2, particularly preferably an elevation density of at least 200 elevations per cm2. Such high elevation densities are accompanied by small-sized elevations. The stability of the flat material web section is then only slightly impaired by the elevations and the end-side through openings. On the other hand, limiting the elevation density is also advantageous in order to achieve sufficiently large distances between adjacent elevations. The flat material web section on the first side preferably has an elevation density of at most 1000 elevations per cm2, preferably an elevation density of at most 500 elevations per cm2.Particularly preferably, the flat material web section has an elevation density of at least 200 elevations per cm2 to at most 400 elevations per cm2. Preferably, the diameter of the end-side through-openings is at least 100 pm, preferably at least 200 pm. Preferably, the diameter of the end-side through-openings is at most 1000 pm, preferably at most 500 pm. Particularly preferably, the diameter of the end-side through-openings is at least 200 pm and at most 500 pm.

[0014] "Airtight sealing" here means that, taking into account the vacuum source used, the negative pressure required for negative pressure wound therapy can be maintained. Therefore, covering layers with minimal gas permeability can also be used, as long as the negative pressure required for negative pressure therapy can be maintained.

[0015] The same applies to the understanding of the term "vacuum-tight fluidic connection." A "vacuum-tight fluidic connection" is understood here to mean that, taking into account the vacuum source used, the negative pressure required for negative pressure wound therapy can be maintained in the fluidically connected cavities.

[0016] Typically, negative pressure therapy involves setting a pressure difference between the air pressure within the negative pressure wound dressing and the ambient air pressure, ranging from a minimum of 20 mm Hg (millimeters of mercury) to a maximum of 250 mm Hg. 1 mm Hg corresponds to one Torr or 133.322 Pa (Pascal).

[0017] A "smooth side" of a layer should not be understood here to mean that the smooth side is necessarily free of any unevenness. Rather, a "smooth side" means a side that is smooth compared to the structured first side of the flat material web section. Accordingly, unevenness can also be present on a smooth side of a layer, for example due to irregularities in the material thickness of the layer in question. However, in terms of their height, any unevenness is of a smaller order of magnitude than the elevations on the structured first side of the flat material web section.

[0018] According to a preferred embodiment, the elevations are conical, cylindrical, truncated pyramid-shaped, or hyperboloid-shaped. Such elevations can be easily introduced into the flat material web or the flat material web section using a simple process. In addition, a highly branched interspace is created, which is accompanied by an effective distribution of wound exudate in the surface directions. The elevations are preferably arranged in island-like, isolated from one another. The elevations preferably have a height of 200 μm to 1000 μm.

[0019] According to a preferred embodiment, at least in a central region of the flat material web section, each of the elevations is surrounded by three to eight additional elevations, whereby the additional elevations together form a regular polygon. The resulting intermediate space ensures a particularly effective distribution of wound exudate. Particularly preferably, the additional elevations form a regular hexagon.

[0020] Preferably, a second side of the flat material web section facing away from the structured first side is smooth. It has been shown that the elevations and the space formed therebetween on the first side of the flat material web section are sufficient for effective distribution of wound exudate in the surface directions. A flat material web section with a structured first side and a smooth second side is easy to produce.

[0021] The elevations are preferably produced by vacuum deep drawing. Such a formation of the elevations can be integrated into the production of the flat material web or the flat material web section in a time-saving manner. For example, a calendered or extruded, still molten flat material web, in particular a plastic film web, is guided over a rotating vacuum perforating roller. The flat material web is then drawn section by section into holes in the vacuum perforating roller by a vacuum in the vacuum perforating roller, whereby the elevations are formed. The shape of the resulting elevations is determined, for example, by the contour of the holes and by the vacuum used. The vacuum in the vacuum perforating roller is preferably set such that the end sides of at least some of the elevations open. The elevations and the through openings are then formed in the same process step.

[0022] According to a preferred embodiment, the flat material web section is made of polyethylene, polyurethane, polyvinyl chloride, or mixtures thereof. Due to their properties, these plastics are particularly suitable for forming the flat material web section. Thus, the plastics are sufficiently flexible to produce a wound dressing with advantageous drapability. Furthermore, a sufficiently rigid flat material web section can be produced to ensure that the continuous interspace is maintained even when a negative pressure is created.

[0023] According to a preferred embodiment, the distribution layer is arranged in the receiving space such that the elevations point toward the cover layer. In the elevations, the wound exudate is transported by capillary forces toward the end openings. If the elevations extend away from the lower layer, the capillary forces accordingly support the transport of wound exudate through the flat material web section.

[0024] According to a preferred embodiment, at least one further distribution layer is arranged in the receiving space, which extends in two surface directions and is designed to distribute wound exudate in the surface directions, that the further distribution layer is formed from a flat material web section, that a first side of the flat material web section is structured by elevations formed integrally with a plane of the flat material web section, that in at least some of the elevations, in particular in all elevations, an end-side through opening is formed, that a continuous intermediate space is formed between the elevations, so that wound exudate can be distributed in the intermediate space in the surface directions, and that the distribution layers are arranged stacked one on top of the other. If two layers are stacked one on top of the other, the sides of the two layers extend parallel to one another.The layers can be stacked directly on top of one another. However, at least one further layer can also be arranged between the two layers. The additional distribution layer can increase the wound dressing's capacity for wound exudate. The features described in connection with the distribution layer can be used to further configure the additional distribution layer.

[0025] Preferably, the distribution layer and the further distribution layer are of identical design. However, the distribution layer and the further distribution layer may also differ from each other in at least one feature, for example, in the material composition and / or the shape of the elevations.

[0026] The distribution layer and the further distribution layer are preferably arranged such that the elevations of the distribution layers protrude in the same direction. Such an arrangement ensures that the aforementioned capillary forces support the transport of wound exudate in the same direction. The distribution layer and the further distribution layer are preferably arranged such that the elevations protrude in the direction of the cover layer. If the distribution layer and the further distribution layer are stacked directly on top of one another, this also has the advantage that the space between the elevations of one distribution layer is not blocked by the elevations of the other distribution layer. Such a blockage of the space could otherwise at least make it more difficult to distribute the wound exudate and / or the negative pressure in the surface directions.

[0027] According to a preferred embodiment, at least one absorption layer is arranged in the receiving space, which absorption layer is designed to absorb wound exudate and to store absorbed wound exudate. The absorption layer increases the capacity of the wound dressing for wound exudate. Preferably, the absorption layer for absorbing and storing wound exudate comprises a hydrophilic material. Suitable hydrophilic materials include, for example, superabsorbent polymers, superabsorbent fibers, cellulose and / or a hydrophilic nonwoven material. The presence of the absorption layer is preferred. However, the disclosure also covers wound dressings in which no absorption layer is arranged in the receiving space.

[0028] The distribution layer or at least one of the distribution layers is preferably arranged between the absorption layer and the wound contact layer. This has the effect that wound exudate is distributed in the surface directions by the distribution layer before being absorbed into the absorption layer. This can increase the absorption efficiency of the absorption layer because a larger surface area of ​​the absorption layer is used to absorb wound exudate. Furthermore, the distribution of wound exudate in the surface directions can prevent clogging of the absorption layer. Such clogging could result from concentrated, undistributed wound exudate accumulations in the absorption layer. The distribution layer or at least one of the distribution layers is preferably arranged between the absorption layer and the cover layer.This prevents clogging of the absorption layer on the side facing the cover layer. The distribution layer arranged between the absorption layer and the cover layer also prevents individual areas of the absorption layer from being isolated from the negative pressure. Such isolation of individual areas could impair the efficiency of the wound dressing with regard to draining wound exudate from the wound.

[0029] According to a preferred embodiment, the absorption layer is in direct contact with the distribution layer and / or the further distribution layer. This direct contact ensures an effective transfer of wound exudate from one of the layers to the other.

[0030] According to a preferred embodiment, at least one further absorption layer is arranged in the receiving space, which is designed to absorb wound exudate and to store absorbed wound exudate, and that the absorption layer and the further absorption layer are arranged stacked one above the other. The amount of absorbent material present can be increased by means of the further absorption layer. Compared with only one correspondingly larger absorption layer, this has the advantage that the surface area available for absorption is increased. The features described in connection with the absorption layer can be used to further configure the further absorption layer. The absorption layer and the further absorption layer are preferably designed identically.However, the absorption layer and the further absorption layer can also differ from each other in at least one feature, for example in their layer thickness and / or their material composition.

[0031] Preferably, the distribution layer or at least one of the distribution layers is arranged between the absorption layer and the further absorption layer. This can increase the absorption efficiency of the absorption layer arranged closer to the cover layer. This results from the fact that, due to the lateral distribution of wound exudate between the two absorption layers, a larger surface area of ​​the absorption layer arranged closer to the cover layer is used to absorb wound exudate.

[0032] Various preferred embodiments of the wound dressing are listed below, which differ from one another in the specific combination of layers arranged in the receiving space. In a first particularly preferred embodiment of the wound dressing, only one distribution layer is arranged in the receiving space. A further distribution layer or an absorption layer is not present. In a second particularly preferred embodiment of the wound dressing, only one distribution layer and one further distribution layer are arranged in the receiving space. In a third particularly preferred embodiment of the wound dressing, only one distribution layer and one absorption layer are arranged in the receiving space. The distribution layer is arranged between the absorption layer and the wound contact layer or between the absorption layer and the cover layer.In a fourth particularly preferred embodiment of the wound dressing, only one distribution layer, one further distribution layer and one absorption layer are arranged in the receiving space. The distribution layer and the further distribution layer are arranged on a respective opposite side of the absorption layer. In a fifth particularly preferred embodiment of the wound dressing, one absorption layer and one further absorption layer are arranged in the receiving space. A distribution layer is arranged between the two absorption layers. A further distribution layer is arranged on a side of the absorption layer facing away from the further absorption layer. A further distribution layer is arranged on a side of the further absorption layer facing away from the absorption layer.

[0033] According to a preferred embodiment, the cover layer comprises a central region and an edge region surrounding the central region, the wound contact layer comprises a central region and an edge region surrounding the central region, and the edge region of the cover layer is connected to the edge region of the wound contact layer, so that the receiving space is only formed between the central region of the cover layer and the central region of the wound contact layer. This has the result that the layers arranged in the receiving space are enclosed in the lateral direction. By connecting the edge region of the wound contact layer to the edge region of the cover layer, the receiving space is formed more or less in the form of a closed pocket.The advantage of connecting the edge regions to one another is that it is not necessary to connect the layers arranged in the receiving space to the wound contact layer and / or the covering layer, nor is it necessary to connect the layers arranged in the receiving space to one another. This eliminates the need for process steps involving the connection of layers during the manufacture of the wound dressing, resulting in cost savings.

[0034] Preferably, the edge region of the cover layer and the edge region of the wound contact layer are connected to each other by an adhesive bond or a welded bond. The bond can be flat, linear, or point-like. An adhesive bond can be created, for example, by applying an adhesive or using an adhesive tape.

[0035] A welded connection can be made, for example, using heat or ultrasound. According to a preferred embodiment, the cover layer projects laterally beyond the wound contact layer, and at least one section of the cover layer projecting laterally beyond the wound contact layer is adhesive. This makes it possible to achieve particularly stable attachment of the wound dressing to the skin surrounding the wound. Because the cover layer projects laterally beyond the wound contact layer, when the wound dressing is applied as intended, the cover layer only comes into contact with the skin surrounding the wound and not with the base of the wound. Accordingly, strongly adhering adhesives which are not intended to come into direct contact with the base of the wound can also be used on the section projecting laterally beyond the wound contact layer.According to an alternative embodiment, the covering layer extends laterally up to the edge of the wound contact layer, but not beyond the edge. When the wound dressing is applied as intended, only the wound contact layer is in direct contact with the tissue, but not the covering layer.

[0036] Preferably, an air-permeable and liquid-impermeable filter unit is assigned to the connection opening, which filtering effect between the receiving space and the environment. Because the filter unit is designed to be air-permeable, a negative pressure can be communicated through the filter unit into the receiving space. Because the filter unit is liquid-impermeable, the filter unit prevents wound exudate from escaping from the wound dressing when the wound dressing is used in negative pressure therapy. Wound exudate escaping from the wound dressing could otherwise contaminate and / or damage the downstream negative pressure source. Preferably, the filter unit is arranged on a side of the cover layer facing the wound contact layer, i.e. in the receiving space.

[0037] The wound contact layer preferably comprises a perforated film. In a perforated film, a plurality of through-openings are formed in the film, for example by punching. Accordingly, wound exudate can be distributed along the wound contact layer and drained into the receiving space. The perforated film is preferably a perforated plastic film.

[0038] According to a preferred embodiment, the wound contact layer comprises a silicone or a hydrogel. A silicone or a hydrogel is particularly suitable for forming the wound contact layer. This results from the fact that silicones and hydrogels typically adhere sufficiently strongly to dry tissue, such as the skin surrounding the wound, for secure attachment of the wound dressing. On the other hand, silicones and hydrogels adhere at most slightly to moist or wet tissue, such as the wound bed, so that sticking to the wound bed is avoided. The wound contact layer particularly preferably comprises a perforated film, in particular perforated plastic film, which is coated with a silicone or a hydrogel on its side facing away from the cover layer.

[0039] The wound dressing is preferably packaged as a pre-applied dressing in an outer packaging. A pre-applied dressing is a wound dressing in which the individual layers are already bonded together as intended during storage. Such a pre-applied dressing is uncomplicated to use.

[0040] The object to be achieved is also achieved by a negative pressure wound therapy kit comprising a wound dressing with the features described above. The negative pressure wound therapy kit according to the invention also comprises a connecting device with an elongated single- or multi-lumen connecting tube comprising a distal end section and a proximal end section, wherein the distal end section can be fluidically connected to the connection opening in a vacuum-tight manner, and wherein the proximal end section can be fluidically connected to a vacuum source in a vacuum-tight manner.

[0041] The terms “distal” and “proximal” describe the arrangement relative to the negative pressure source. A proximal section of an element is located closer to the negative pressure source than a distal section of the same element. In this respect, for example, the proximal end section of the connecting hose is located closer to the negative pressure source than the distal end section when the connecting hose is used as intended. With regard to the advantages achievable with the negative pressure wound therapy kit, reference is made to the relevant information on the wound dressing. The features described in connection with the wound dressing can be used to further design the negative pressure wound therapy kit.

[0042] The object to be achieved is also achieved by a negative pressure wound therapy system comprising a negative pressure wound therapy kit with the features described above. The negative pressure wound therapy system according to the invention also comprises a negative pressure source, wherein the proximal end section of the connecting tube can be fluidly connected to the negative pressure source in a vacuum-tight manner.

[0043] Regarding the advantages achievable with the negative pressure wound therapy system, reference is made to the relevant information on the wound dressing. The features described in connection with the wound dressing can be used to further refine the negative pressure wound therapy system.

[0044] The invention is described in more detail below with reference to the figures, wherein identical or functionally identical elements are provided with reference numerals only once, if appropriate. The figures serve as examples and are not to be understood as limiting. Fig. 1 shows a negative pressure wound therapy system with a

[0045] wound dressing,

[0046] Fig. 2 is a sectional view of a first embodiment of the wound dressing,

[0047] Fig. 3 is a plan view of a distribution layer of the wound dressing,

[0048] Fig. 4 is a sectional view of the distribution layer shown in Figure 3 along the section line AA,

[0049] Fig. 5 is a sectional view of a second embodiment of the wound dressing,

[0050] Fig. 6 is a sectional view of a third embodiment of the wound dressing,

[0051] Fig. 7 is a sectional view of a fourth embodiment of the wound dressing and

[0052] Fig. 8 is a sectional view of a fifth embodiment of the wound dressing.

[0053] Figure 1 shows a negative pressure wound therapy system 10 for use in the negative pressure therapy of wounds. The negative pressure wound therapy system 10 comprises a negative pressure source 12 and a negative pressure wound therapy kit 14. The negative pressure wound therapy kit 14 comprises a wound dressing 16 and a connecting device 18. The connecting device 18 comprises an elongated single-lumen or multi-lumen connecting tube 20 with a proximal end section 22 and a distal end section 24. The proximal end section 22 can be fluidly connected to the negative pressure source 12 in a vacuum-tight manner. The distal end section 24 can be fluidly connected to a connection opening 26 in the wound dressing 16 in a vacuum-tight manner. For this purpose, the distal end section 24 comprises a fluid inlet 25.In the negative pressure wound therapy system 10 shown in Figure 1, the distal end section 24 is already connected to the connection opening 26, so that the connection opening 26 is covered by the distal end section 24.

[0054] The structure of the wound dressing 16 is explained in more detail below with additional reference to Figure 2. Figure 2 shows a schematic sectional view of a first exemplary embodiment of the wound dressing 16. It should be noted that, for the sake of clarity, layers of the wound dressing 16 stacked directly on top of one another are shown spaced apart from one another in Figure 2. In contrast to this illustration, when the wound dressing 16 is used, layers of the wound dressing 16 stacked directly on top of one another are in direct contact.

[0055] The wound dressing 16 comprises a wound contact layer 28. The wound contact layer 28 comprises a smooth first side 30 for application to the base of a wound and a smooth second side 32 facing away from the first side 30. The wound dressing 16 also comprises an air-impermeable cover layer 34 for hermetically closing the wound. The previously mentioned connection opening 26 is formed in the cover layer 34. Preferably, the cover layer 34 comprises a plastic film, in particular a polyurethane film. A receiving space 36 is formed between the wound contact layer 28 and the cover layer 34.

[0056] The wound contact layer 28 is designed to be liquid-permeable to drain wound exudate from the wound into the receiving space 36. In the present case, the wound contact layer 28 comprises a plastic film coated with a silicone or a hydrogel on its wound-facing side. The wound contact layer 28, i.e. the plastic film together with the silicone or hydrogel, is perforated. In this respect, the wound contact layer 28 comprises a plurality of perforations or through openings distributed throughout the wound contact layer 28. Wound exudate can be drained from the wound space into the receiving space 36 through the perforations.

[0057] The wound contact layer 28 comprises a central region 38 and an edge region 40 surrounding the central region 38. The cover layer 34 comprises a central region 42 and an edge region 44 surrounding the central region 42. In the present case, the edge region 40 of the wound contact layer 28 is peripherally connected to the edge region 44 of the cover layer 34. The receiving space 36 is accordingly formed only between the central region 38 of the wound contact layer 28 and the central region 42 of the cover layer 34.

[0058] Preferably, the edge regions 40 and 44 are connected to one another by an adhesive bond. Particularly preferably, a side of the cover layer 34 facing the wound contact layer 28 is coated with an adhesive, for example, an acrylate adhesive, at least in the edge region 44. Alternatively, the edge regions 40 and 44 are connected to one another by a welded joint.

[0059] The interconnection of the edge regions 40 and 44 ensures that additional layers arranged in the receiving space 36 are securely held in the receiving space 36. Accordingly, only slight slippage of these layers is possible. This results in the advantage that a connection between the layers arranged in the receiving space 36 and a connection of the layers to the wound contact layer 28 and / or to the cover layer 34 can be dispensed with.

[0060] When the wound dressing 16 is applied to the wound, the distal end section 24 is fluidly connected to the connection opening 26 in a vacuum-tight manner, and the proximal end section 22 is fluidly connected to the vacuum source 12 in a vacuum-tight manner, a vacuum can be created between the covering layer 34 and the wound by the vacuum source 12 in order to effectively drain wound exudate from the wound. In the exemplary embodiments illustrated in the figures, the edge region 44 of the covering layer 34 protrudes at most up to an edge 48 of the wound contact layer 28, but not beyond the edge 48. Accordingly, when the wound dressing 16 is applied as intended, the covering layer 34 does not come into contact with the skin surrounding the wound. According to a further embodiment, the edge region 44 of the cover layer 34 projects laterally beyond the edge 48 of the wound contact layer 28, at least in sections.This has the advantage that a particularly secure attachment of the wound dressing 16 to the tissue can be achieved. The aforementioned adhesive on the side of the covering layer 34 facing the wound contact layer 28 then comes into contact with the skin surrounding the wound. Such a lateral projection of the covering layer 34 is indicated by dashed lines in Figure 2.

[0061] The wound dressing 16 also includes an air-permeable and liquid-impermeable filter unit 72. The filter unit 72 is assigned to the connection opening 26 and acts as a filter between the receiving space 36 and the environment. In this case, the filter unit 72 is arranged on the side of the cover layer 34 facing the wound contact layer 28.

[0062] In the first embodiment of the wound dressing 16 shown in Figure 2, a distribution layer 50 is arranged in the receiving space 36. The design of the distribution layer 50 is explained in more detail below with additional reference to Figures 3 and 4. Figure 3 shows a plan view of the distribution layer 50. Figure 4 shows a sectional view of the distribution layer 50 along the section line AA shown in Figure 3.

[0063] The distribution layer 50 extends in two surface directions X and Y and is designed to distribute wound exudate in the surface directions X and Y. Furthermore, the distribution layer 50 promotes distribution of the negative pressure created in the wound space. The distribution layer 50 is formed by a flat material web section 52. The flat material web section 52 comprises a plane 54 with a first side 56 and a second side 58 facing away from the first side 56.

[0064] The first side 56 of the flat material web section 52 is structured by elevations 60 formed integrally with the plane 54. In at least some of the elevations 60, an end-side through-opening 64 is formed in the raised end sides 62 of the respective elevations 60. In the present case, an end-side through-opening 64 is formed in each of the elevations 60. A continuous intermediate space 66 is formed between the elevations 60, such that wound exudate can be distributed in the surface directions X and Y in the intermediate space 66. The second side 58 of the flat material web section 52, facing away from the structured first side 56, is smooth. The flat material web section 52 preferably has an elevation density of at least 200 elevations per cm2 to at most 400 elevations 60 per cm2 on the first side 56. In this case, the survey density is 280 surveys, 60 per cm2.Preferably, the diameter of the end through openings 64 is at least 200 pm and at most 500 pm.

[0065] To form the continuous intermediate space 66, the elevations 60 are arranged in island-like configurations, isolated from one another. In the illustrated embodiment, the elevations 60 are shaped like a single-layer hyperboloid. In this case, the elevations 60 are thus hyperboloid-shaped. A peripheral wall of the elevations 60 is anticlastically curved for this purpose. Alternatively, the elevations 60 are preferably conical, i.e., truncated cone-shaped, cylindrical, or truncated pyramid-shaped.

[0066] The elevations 60 are preferably distributed such that, at least in a central region of the flat material web section 52, each of the elevations 60 is surrounded by three to eight further elevations 60, wherein the further elevations 60 together form a regular polygon. In the present case, the further elevations 60 together form a regular hexagon. At least in the central region of the flat material web section 52, each of the elevations 60 is therefore surrounded by six further elevations 60. Such an arrangement of the elevations 60 leads to a particularly uniform distribution of wound exudate in the surface directions X and Y.

[0067] The flat material web section 52 is presently a plastic film 52. The plastic film 52 is preferably made of polyethylene, polyurethane, polyvinyl chloride, or a mixture thereof. These plastics have the advantage that, on the one hand, a flexibly deformable distribution layer 50 can be obtained. This results in a wound dressing 16 with advantageous drapability. In addition, the aforementioned plastics also exhibit sufficient rigidity. In this respect, the plastics ensure that the continuous gap 66 is maintained when the wound dressing 16 is used, despite the negative pressure created.

[0068] The elevations 60 are produced by vacuum deep drawing. For this purpose, the extruded or calendered, still molten flat material web, in particular a plastic film web, is preferably guided over a rotating vacuum perforating roller. The flat material web is then drawn into holes in the vacuum perforating roller in some areas by a vacuum in the vacuum perforating roller, whereby the elevations 60 are formed. The shape of the resulting elevations 60 is determined, for example, by the contour of the holes and by the vacuum used. Preferably, the vacuum in the vacuum perforating roller is set such that the end sides 62 of the elevations 60 open. The elevations 60 and the through openings 64 are thus formed in the same

[0069] Process step formed.

[0070] The distribution layer 50 is arranged in the receiving space 36 such that the elevations 60 protrude in the direction of the covering layer 34. This supports the transport of wound exudate through the distribution layer 50 in the direction of the covering layer 34. Specifically, capillary forces act on the wound exudate in the elevations 60, promoting transport in the direction of the covering layer 34.

[0071] Various further exemplary embodiments of the wound dressing 16 are schematically illustrated in Figures 5 to 8. The exemplary embodiments disclosed in Figures 5 to 8 differ from the exemplary embodiment illustrated in Figure 2 with regard to the layers arranged in the receiving space 36. With regard to the formation of the wound contact layer 28, the cover layer 34 and any existing distribution layers 50, reference is made to the above explanations regarding these layers. The wound dressings 16 illustrated in Figures 5 to 8 can also be present as a wound dressing in the negative pressure wound therapy kit 14 or in the negative pressure wound therapy system 10.

[0072] Figure 5 shows a sectional view of a second embodiment of the wound dressing 16. In the wound dressing 16 shown in Figure 5, a distribution layer 50 and an absorption layer 70 are arranged in the receiving space 36.

[0073] The absorption layer 70 is designed to absorb wound exudate and to store absorbed wound exudate. Various materials, particularly hydrophilic ones, can be used to form the absorption layer 70. Preferably, the absorption layer 70 comprises superabsorbent polymers, superabsorbent fibers, cellulose, and / or a hydrophilic nonwoven material.

[0074] The distribution layer 50 and the absorption layer 70 are arranged directly stacked on top of one another in the receiving space 36, such that the distribution layer 50 is in direct contact with the absorption layer 70. The distribution layer 50 is arranged between the absorption layer 70 and the wound contact layer 28. The elevations 60 of the distribution layer 50 face the absorption layer 70. The lateral distribution of wound exudate in the intermediate space 66 ensures that a large part of the surface of the absorption layer 70 is used to absorb wound exudate. This prevents blockage of the absorption layer 70. Such blockage would be more likely if the wound exudate were only absorbed by the absorption layer 70 at a few isolated locations.

[0075] Figure 6 shows a sectional view of a third embodiment of the wound dressing 16. In the wound dressing 16 shown in Figure 5, a first distribution layer 50-1 and a second distribution layer 50-2 are arranged in the receiving space 36.

[0076] The first distribution layer 50-1 and the second distribution layer 50-2 are stacked one above the other in the receiving space 36 in such a way that the elevations 60 of the distribution layers 50-1 and 50-2 protrude in the same direction, in this case in the direction of the cover layer 34. As a result, the capillary forces act both in the elevations 60 of the first distribution layer 50-1 and in the elevations 60 of the second distribution layer 50-2 in the direction of the cover layer 34. By providing two distribution layers 50-1 and 50-2, the capacity of the wound dressing 16 for wound exudate can be increased.

[0077] Figure 7 shows a sectional view of a fourth embodiment of the wound dressing 16. In the wound dressing 16 shown in Figure 7, a first distribution layer 50-1, a second distribution layer 50-2, and an absorption layer 70 are arranged in the receiving space 36.

[0078] The distribution layers 50-1 and 50-2 are arranged on respective opposite sides of the absorption layer 70. The first distribution layer 50-1 is arranged between the wound contact layer 28 and the absorption layer 70. The second distribution layer 50-2 is arranged between the cover layer 34 and the absorption layer 70. The distribution layers 50-1 and 50-2 are arranged such that the elevations 60 point in the same direction, in this case in the direction of the cover layer 34. The second distribution layer 50-2 prevents individual regions of the absorption layer 70 from being isolated from the negative pressure. Such isolation of individual regions could impair the efficiency of the wound dressing 16 with regard to the drainage of wound exudate from the wound.

[0079] Figure 8 shows a sectional view of a fifth embodiment of the wound dressing 16. In the wound dressing 16 shown in Figure 8, a first distribution layer 50-1, a second distribution layer 50-2, a third distribution layer 50-3, a first absorption layer 70-1, and a second absorption layer 70-2 are arranged in the receiving space.

[0080] The second distribution layer 50-2 is arranged between the first absorption layer 70-1 and the second absorption layer 70-2. The first distribution layer 50-1 is arranged on a side of the first absorption layer 70-1 facing away from the second absorption layer 70-2. The third distribution layer 50-3 is arranged on a side of the second absorption layer 70-2 facing away from the first absorption layer 70-1. The distribution layers 50-1, 50-2 and 50-3 are arranged in the receiving space 36 such that their elevations 60 protrude in the same direction, in this case in the direction of the cover layer 34.

Claims

Patent claims A wound dressing (16) for use in negative pressure therapy of wounds, comprising a wound contact layer (28) for application to the base of a wound, wherein the wound contact layer (28) comprises a smooth first side (30) and a smooth second side (32) facing away from the first side (30), with an air-impermeable cover layer (34) for airtight closure of the wound, wherein a receiving space (36) is formed between the cover layer (34) and the wound contact layer (28), wherein the wound contact layer (28) is designed to be liquid-permeable for draining wound exudate from the wound into the receiving space (36), and wherein a connection opening (26) for vacuum-tight fluidic connection of the receiving space (36) to a vacuum source (12) is formed in the cover layer (34), and with at least one distribution layer (50) arranged in the receiving space (36), wherein the Distribution layer (50) extends in two surface directions (X,Y) and is designed to distribute wound exudate in the surface directions (X,Y), characterized in that the distribution layer (50) is formed by a flat material web section (52), that a first side (56) of the flat material web section (52) is structured by elevations (60) formed integrally with a plane (54) of the flat material web section (52), that in at least some of the elevations (60), in particular in all elevations (60), an end-side through-opening (64) is formed, and that between the elevations (60) a continuous intermediate space (66) is formed, so that wound exudate in the intermediate space (66) can be distributed in the surface directions (X, Y).

2. Wound dressing (16) according to claim 1, characterized in that the elevations (60) are conical, cylindrical, truncated pyramid-shaped or hyperboloid-shaped.

3. Wound dressing (16) according to one of claims 1 and 2, characterized in that at least in a central region of the flat material web section (52) each of the elevations (60) is surrounded by three to eight further elevations (60), wherein the further elevations (60) together form a regular polygon, in particular a regular hexagon.

4. Wound dressing (16) according to one of claims 1 to 3, characterized in that a second side (58) of the flat material web section (52) facing away from the structured first side (56) is smooth.

5. Wound dressing (16) according to one of claims 1 to 4, characterized in that the elevations (60) are manufactured by vacuum deep drawing.

6. Wound dressing (16) according to one of claims 1 to 5, characterized in that the flat material web section (52) is made of polyethylene, polyurethane, polyvinyl chloride or mixtures thereof.

7. Wound dressing (16) according to one of claims 1 to 6, characterized in that the distribution layer (50) is arranged in the receiving space (36) in such a way that the elevations (60) protrude in the direction of the cover layer (34).

8. Wound dressing (16) according to one of claims 1 to 7, characterized in that at least one further distribution layer (50) is arranged in the receiving space (36), which extends in two surface directions (X, Y) and is designed to distribute wound exudate in the surface directions (X, Y), that the further distribution layer (50) is formed by a flat material web section (52), that a first side (56) of the flat material web section (52) is structured by elevations (60) formed integrally with a plane (54) of the flat material web section (52), that in at least some of the elevations (60), in particular in all elevations (60), an end-side through-opening (64) is formed, that between the elevations (64) a continuous intermediate space (66) is formed, so that wound exudate can be distributed in the intermediate space (66) in the surface directions (X,Y), and that the distribution layer (50) and the further distribution layer (50) are arranged stacked one above the other.

9. Wound dressing (16) according to claim 8, characterized in that the distribution layer (50) and the further distribution layer (50) are arranged such that the elevations of the distribution layers (50) protrude in the same direction.

10. Wound dressing (16) according to one of claims 1 to 9, characterized in that at least one absorption layer (70) is arranged in the receiving space (36), which absorption layer is designed to absorb wound exudate and to store absorbed wound exudate.

11. Wound dressing (16) according to claim 10, characterized in that the distribution layer (50) or at least one of the distribution layers (50) is arranged between the absorption layer (70) and the wound contact layer (28).

12. Wound dressing (16) according to one of claims 10 and 11, characterized in that the distribution layer (50) or at least one of the distribution layers (50) is arranged between the absorption layer (70) and the cover layer (34).

13. Wound dressing (16) according to one of claims 10 to 12, characterized in that the absorption layer (70) is in direct contact with the distribution layer (50) and / or the further distribution layer (50).

14. Wound dressing (16) according to one of claims 10 to 13, characterized in that at least one further absorption layer (70) is arranged in the receiving space (36), which is designed to absorb wound exudate and to store absorbed wound exudate, and in that the absorption layer (70) and the further absorption layer (70) are arranged stacked one above the other.

15. Wound dressing (16) according to claim 14, characterized in that the distribution layer (50) or at least one of the distribution layers (50) is arranged between the absorption layer (70) and the further absorption layer (70).

16. Wound dressing (16) according to one of claims 1 to 15, characterized in that the cover layer (34) comprises a central region (42) and an edge region (44) surrounding the central region (42), that the wound contact layer (28) comprises a central region (38) and an edge region (40) surrounding the central region (38), and that the edge region (44) of the cover layer (34) is connected to the edge region (40) of the wound contact layer (28), so that the receiving space (36) only between the central region (44) of the cover layer (34) and the central region (38) of the wound contact layer (28).

17. Wound dressing (16) according to one of claims 1 to 16, characterized in that the cover layer (34) projects laterally beyond the wound contact layer (28), and that at least one section of the Cover layer (34) is adhesive.

18. Wound dressing (16) according to one of claims 1 to 17, characterized in that the connection opening (26) is assigned an air-permeable and liquid-impermeable filter unit (72) which has a filtering effect between the receiving space (36) and the environment.

19. Wound dressing (16) according to one of claims 1 to 18, characterized in that the wound contact layer (28) comprises a perforated film.

20. Wound dressing (16) according to one of claims 1 to 19, characterized in that the wound contact layer (28) comprises a silicone or a hydrogel.

21. Wound dressing (16) according to one of claims 1 to 20, characterized in that it is packaged as a ready-made dressing in an outer packaging.

22. Negative pressure wound therapy kit (14) with a wound dressing (16) according to one of claims 1 to 21 and comprising a connecting device (18) which comprises an elongated single- or multi-lumen connecting tube (20) with a distal end section (24) and a proximal end section (22), wherein the distal end section (24) can be fluidically connected to the connection opening (26) in a vacuum-tight manner, and wherein the proximal end section (22) can be fluidically connected to a vacuum source (12) in a vacuum-tight manner.

23. Negative pressure wound therapy system (10) with a negative pressure wound therapy kit (14) according to claim 22 and with a negative pressure source (12), wherein the proximal end section (22) of the connecting tube (20) can be fluidly connected to the negative pressure source (12) in a negative pressure-tight manner.

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