Wound dressing for negative pressure treatment of wounds, negative pressure wound treatment kit and negative pressure wound treatment system

Abstract

The invention relates to a wound dressing (16) for the negative pressure treatment of a wound, comprising: a wound contact layer (28); a gas-tight cover layer (34), a receiving space (36) being formed between the cover layer and the wound contact layer, the wound contact layer being designed to be liquid-permeable for discharging wound exudate from the wound into the receiving space, and a connection opening (26) being formed in the cover layer; and at least one distribution layer (50) arranged in the receiving space, the distribution layer extending in two planar directions (X, Y) and being designed to distribute wound exudate in these planar directions, the invention proposes that the distribution layer is formed by a flat material web section (52); the first side (56) of the flat material web section is structured by means of a projection (60) integrally formed in a plane (54) of the flat material web section; end-side through holes (64) are formed in at least some of the protrusions; and a continuous gap (66) is formed between the projections.

Description

Technical Field

[0001] The present invention relates to a wound dressing for negative pressure wound treatment. In addition, the present invention also relates to a negative pressure wound treatment kit including such a wound dressing. In addition, the present invention also relates to a negative pressure wound treatment system, which includes a negative pressure source and such a negative pressure wound treatment kit. Background Art

[0002] Negative pressure wound treatment, also known as NPWT (Negative-Pressure Wound Therapy), is an innovative wound treatment method applicable to a variety of indications. Among them, for example, it includes acute skin or soft tissue defects, wound healing disorders, chronic wounds, etc. The purpose of negative pressure treatment is to stimulate granulation tissue growth and promote the healing process. For this purpose, within the scope of negative pressure treatment, negative pressure is generated in the wound area, so that wound exudate can be effectively drained from the wound.

[0003] The wound dressings used in negative pressure treatment generally include a wound contact layer for applying to the wound surface and an airtight cover layer for gas-tightly closing the wound. An accommodation space is formed between the wound contact layer and the cover layer. The wound contact layer is designed to be liquid-permeable for draining wound exudate from the wound into the accommodation space. The cover layer includes a connection opening for establishing a negative pressure-sealed fluid connection between the accommodation space and the negative pressure source. When the wound dressing is applied to the wound as expected and the negative pressure source is fluid-connected to the connection opening in a negative pressure-sealed manner, negative pressure can be generated in the wound site and the accommodation space by the negative pressure source. In known wound dressings, at least one distribution layer is usually arranged in the accommodation space. The at least one distribution layer extends in two planar directions and is designed to distribute wound exudate along these planar directions. Hereinafter, the distribution along these planar directions is also referred to as lateral distribution. By the lateral distribution of wound exudate, the accumulation of wound exudate and the possible accompanying blockage of the components of the wound dressing are avoided. In addition, the distribution layer also facilitates the lateral distribution of negative pressure in the wound site.

[0004] For example, a wound dressing of this type is known from patent documents EP 3 287 106 B1 and EP 2 879 636 B1. In these patent documents, various materials are proposed for the distribution layer, such as open-cell foam materials, spacer fabrics or non-woven fabrics. Although such materials meet the basic requirements of the distribution layer. But the cost of using these materials is relatively high. This is clearly tolerated in previously known wound dressings. Summary of the Invention

[0005] The object on which the present invention is based is to provide, in a wound dressing for negative pressure wound treatment, the possibility of ensuring an effective lateral distribution of wound exudate in the receiving space by means of a cost-effective device.

[0006] According to the invention, this object is achieved by a wound dressing according to claim 1, a negative pressure wound treatment kit according to claim 22, and a negative pressure wound treatment system according to claim 23.

[0007] The dependent claims and the description give advantageous variants and embodiments.

[0008] Thus, the present invention provides a wound dressing for treating a wound under negative pressure. The wound dressing includes a wound contact layer for applying to the wound surface. The wound contact layer includes a smooth first side and a smooth second side facing away from the first side. In addition, the wound dressing according to the invention includes an airtight cover layer for gas-tightly closing the wound.

[0009] A receiving space is formed between the cover layer and the wound contact layer. The wound contact layer is designed to be liquid-permeable for discharging wound exudate from the wound into the receiving space. Preferably, the wound contact layer is designed to be perforated so that wound exudate can pass through the wound contact layer via perforations or through-holes formed in the wound contact layer. However, the wound contact layer can also be designed to be essentially liquid-permeable. A connection opening is formed in the cover layer for establishing a negatively pressurized fluid connection between the receiving space and a negative pressure source. The wound dressing according to the invention further includes at least one distribution layer arranged in the receiving space. The distribution layer extends in two planar directions and is designed to distribute wound exudate in these planar directions.

[0010] In this case, it is proposed that: the distribution layer consists of a flat material web section; the first side of the flat material web section is structurally designed by means of projections integrally formed in the plane of the flat material web section; end-side through-holes are formed in at least some of the projections; and continuous gaps are formed between the projections so that wound exudate can be distributed in the gaps in the planar direction.

[0011] Surprisingly, it has been found that a flat material web section designed in the above manner is particularly suitable in terms of its properties as a distribution layer or as a component of a distribution layer. Through the end-side through-holes, the wound exudate discharged into the receiving space can be conveyed orthogonally to the plane direction through the flat material web section. In the gaps or through the gaps, the wound exudate can be distributed in the plane direction, in particular along the first side of the flat material web section. The flat material web section formed in the above manner can be obtained cost-effectively. This is especially due to the fact that suitable protrusions can be formed in the flat material web or flat material web section at a relatively low time cost. Using the flat material web section in the distribution layer or using the flat material web section as the distribution layer also has the advantage that a wound dressing with high patient comfort can be obtained. This is especially because a wound dressing with a small structural height can be achieved.

[0012] The flat material web section is a section of the flat material web. For example, the flat material web section is cut out from the flat material web. Preferably, the protrusions have been formed in the flat material web. However, the protrusions can also be formed only in the flat material web section. In particular, the flat material web is a plastic film web, so the flat material web section is designed as a plastic film.

[0013] Preferably, the flat material web section has a protrusion density of at least 50 protrusions per cm2, preferably at least 100 protrusions per cm2, particularly preferably at least 200 protrusions per cm2 on the first side. Such a high protrusion density involves small-sized protrusions. Thus, the protrusions and the end-side through-holes only have a slight impact on the stability of the flat material web section. On the other hand, it is also advantageous to limit the protrusion density so that the distance between adjacent protrusions is large enough. Preferably, the flat material web section has a protrusion density of at most 1000 protrusions per cm2, preferably at most 500 protrusions per cm2 on the first side. Particularly preferably, the protrusion density of the flat material web section is from at least 200 protrusions per cm2 to at most 400 protrusions per cm2. Preferably, the diameter of the end-side through-hole is at least 100 µm, preferably at least 200 µm. Preferably, the diameter of the end-side through-hole is at most 1000 µm, preferably at most 500 µm. Particularly preferably, the diameter of the end-side through-hole is at least 200 µm and at most 500 µm.

[0014] Here, "sealed gas-tight" should be understood as: considering the negative pressure source used, the negative pressure required for negative pressure wound treatment can be maintained. Therefore, a covering layer with very low breathability can also be used as long as the negative pressure required for negative pressure treatment can be maintained.

[0015] The corresponding content also applies to the understanding of the term "negatively pressure-sealed fluid connection". Herein, a "negatively pressure-sealed fluid connection" should be understood as: considering the negative pressure source used, a negative pressure required for treating a wound can be maintained in cavities that are fluidly connected to each other.

[0016] Generally, within the scope of negative pressure treatment, a pressure difference is set between the air pressure within a negative pressure wound dressing and the ambient air pressure, and this pressure difference is at least 20 mm Hg (millimeters of mercury) to at most 250 mm Hg. 1 mm Hg is equal to one torr or 133.322 Pa (Pascals).

[0017] Herein, the "smooth side" of a layer should not be understood as necessarily having no unevenness at all. Rather, the "smooth side" refers to the side that is smoother compared to the structured first side of a flat material web section. Correspondingly, there may also be unevenness on the smooth side of a layer, for example, unevenness due to non-uniform material thickness of the relevant layer. However, any unevenness is of a smaller order of magnitude in terms of its height compared to the protrusions on the structured first side of the flat material web section.

[0018] According to a preferred embodiment, the protrusions are designed as conical, cylindrical, frustoconical, or hyperboloidal. Such protrusions can be easily introduced into the flat material web or a flat material web section in terms of process technology. In addition, highly branched gaps are achieved, which involves the effective distribution of wound exudate in the planar direction. Preferably, the protrusions are arranged in an island-like isolation from each other. Preferably, the height of the protrusions is 200 µm to 1000 µm.

[0019] According to a preferred embodiment, it is proposed that: at least in the central region of the flat material web section, each of the protrusions is surrounded by three to eight additional protrusions, and these additional protrusions together form a regular polygon. The gaps thus achieved ensure a particularly effective distribution of wound exudate. Particularly preferably, these additional protrusions form a regular hexagon.

[0020] Preferably, the second side of the flat material web section facing away from the structured first side is designed to be smooth. It has been proven that the protrusions on the first side of the flat material web section and the gaps formed therebetween are sufficient for the effective distribution of wound exudate in the planar direction. A flat material web section having a structured first side and a smooth second side is easy to implement in terms of production technology.

[0021] Preferably, the protrusions are formed by vacuum deep drawing. This way of forming the protrusions can be integrated into the manufacture of the flat material web or the flat material web section in a time-saving manner. For example, for this purpose, a flat material web (especially a plastic film web) that has been calendered or extruded and is still in a molten state is guided onto a rotating, perforated negative pressure roller. Then, the flat material web is locally sucked into the holes of the vacuum perforation roller by the negative pressure in the perforated negative pressure roller, thereby forming the protrusions. Here, the shape of the obtained protrusions is determined, for example, by the contour of the holes and the negative pressure used. Preferably, the negative pressure in the perforated negative pressure roller is adjusted such that the end sides of at least some of the protrusions are open. Thus, the protrusions and the through holes are formed in the same process.

[0022] According to a preferred embodiment, it is proposed that the flat material web section is made of polyethylene, polyurethane, polyvinyl chloride or a mixture thereof. These plastics are particularly suitable for forming the flat material web section due to their properties. Thus, these plastics have sufficient flexibility so that a wound dressing with favorable drapability can be obtained. In addition, a flat material web section with sufficient rigidity can be achieved, thereby ensuring that a continuous gap can still be maintained even when negative pressure is generated.

[0023] According to a preferred embodiment, it is proposed that the distribution layer is arranged in the receiving space in such a way that the protrusions protrude in the direction towards the covering layer. In the protrusions, wound exudate is transported towards the end-side through holes due to capillary forces. If the protrusions extend outwards from the lower layer, the capillary forces contribute to the transport of the wound exudate through the flat material web section.

[0024] According to a preferred embodiment: At least one additional distribution layer is arranged in the receiving space, which additional distribution layer extends in two planar directions and is designed to distribute wound exudate in these planar directions; the additional distribution layer is composed of a flat material web section; the first side of the flat material web section is structurally designed by protrusions integrally formed in the plane of the flat material web section; end-side through holes are formed in at least some of the protrusions, especially in all of the protrusions; continuous gaps are formed between the protrusions such that wound exudate can be distributed in the gap in the planar direction; and these distribution layers are arranged on top of each other. If two layers are arranged on top of each other, the sides of the two layers extend parallel to each other. Here, these layers can be directly arranged on top of each other. However, at least one additional layer can also be arranged between the two layers. By means of this additional distribution layer, the capacity of the wound dressing for wound exudate can be increased. The features described in connection with the distribution layer can be used to further design this additional distribution layer. Preferably, the distribution layer and the additional distribution layer have the same design. However, the distribution layer and the additional distribution layer can also differ from each other in at least one feature, for example, in the material composition and / or shape of the protrusions.

[0025] Preferably, the distribution layer and the additional distribution layer are arranged such that the protrusions of the distribution layer protrude in the same direction. What is achieved by this arrangement is that the capillary forces described above contribute to the transport of wound exudate in the same direction. Preferably, the distribution layer and the additional distribution layer are arranged such that the protrusions protrude in the direction towards the covering layer. If the distribution layer and the additional distribution layer are directly stacked on top of each other, the additional advantage is also obtained that the gaps between the protrusions of one distribution layer are not blocked by the protrusions of the other distribution layer. Otherwise, such a blockage of the gaps may at least make the distribution of wound exudate and / or negative pressure in the planar direction difficult.

[0026] According to a preferred embodiment, at least one absorbent layer is arranged in the receiving space, and the absorbent layer is designed to receive wound exudate and store the received wound exudate. The absorbent layer increases the capacity of the wound dressing for wound exudate. Preferably, in order to receive and store wound exudate, the absorbent layer comprises a hydrophilic material. Suitable hydrophilic materials include, for example, superabsorbent polymers, superabsorbent fibers, cellulose, and / or hydrophilic nonwoven materials. The presence of the absorbent layer is preferred. However, the present disclosure also encompasses wound dressings in which no absorbent layer is arranged in the receiving space.

[0027] Preferably, the distribution layer or at least one of the distribution layers is arranged between the absorbent layer and the wound contact layer. Thus, the wound exudate is distributed in the planar direction through the distribution layer before being received in the absorbent layer. This can improve the absorption efficiency of the absorbent layer, since a larger surface area of the absorbent layer is used to receive the wound exudate. In addition, distributing the wound exudate in the planar direction can also prevent clogging of the absorbent layer. Such clogging may be caused by the accumulation of concentrated and undistributed wound exudate in the absorbent layer.

[0028] Preferably, the distribution layer or at least one of the distribution layers is arranged between the absorbent layer and the covering layer. Thereby, clogging of the absorbent layer on its side facing the covering layer is prevented. By means of the distribution layer arranged between the absorbent layer and the covering layer, isolation of certain regions of the absorbent layer from the negative pressure is also prevented. Such isolation of certain regions may impair the efficiency of the wound dressing in discharging wound exudate from the wound.

[0029] According to a preferred embodiment, the absorbent layer is in direct contact with the distribution layer and / or the additional distribution layer. Such direct contact can ensure an effective transition of wound exudate from one layer to another layer.

[0030] According to a preferred embodiment, at least one additional absorbent layer is arranged in the receiving space, and the additional absorbent layer is designed to receive wound exudate and store the received wound exudate; and the absorbent layer and the additional absorbent layer are arranged one above the other. The amount of absorbent material present can be increased by this additional absorbent layer. The advantage obtained compared to using only one correspondingly large-sized absorbent layer is that the surface area available for absorption is increased. The features described in connection with the absorbent layer can be used for further designing the additional absorbent layer. Preferably, the absorbent layer and the additional absorbent layer have the same design. However, the absorbent layer and the additional absorbent layer can also differ from each other in at least one feature, for example in layer thickness and / or material composition.

[0031] Preferably, at least one distribution layer of the distribution layer or the distribution layers is arranged between the absorbent layer and the additional absorbent layer. This can improve the absorption efficiency of the absorbent layer arranged close to the covering layer. The reason is that based on the lateral distribution of the wound exudate between the two absorbent layers, a larger surface area of the absorbent layer arranged close to the covering layer is used to receive the wound exudate.

[0032] The following will list different preferred embodiments of the wound dressing, which differ from each other in the specific combination of the layers arranged in the receiving space. In a first particularly preferred embodiment of the wound dressing, only the distribution layer is arranged in the receiving space. There is no additional distribution layer or absorbent layer. In a second particularly preferred embodiment of the wound dressing, only the distribution layer and an additional distribution layer are arranged in the receiving space. In a third particularly preferred embodiment of the wound dressing, only the distribution layer and the absorbent layer are arranged in the receiving space. The distribution layer is arranged between the absorbent layer and the wound contact layer or between the absorbent layer and the covering layer. In a fourth particularly preferred embodiment of the wound dressing, only the distribution layer, the additional distribution layer and the absorbent layer are arranged in the receiving space. The distribution layer and the additional distribution layer are respectively arranged on different sides of the absorbent layer. In a fifth particularly preferred embodiment of the wound dressing, the absorbent layer and an additional absorbent layer are arranged in the receiving space. The distribution layer is arranged between the two absorbent layers. An additional distribution layer is arranged on the side of the absorbent layer facing away from the additional absorbent layer. An additional distribution layer is arranged on the side of the additional absorbent layer facing away from the absorbent layer.

[0033] According to a preferred embodiment, the covering layer includes a central region and an edge region surrounding the central region; the wound contact layer includes a central region and an edge region surrounding the central region; and the edge region of the covering layer is connected to the edge region of the wound contact layer such that the receiving space is formed only between the central region of the covering layer and the central region of the wound contact layer. Thus, the layer disposed in the receiving space is surrounded in the lateral direction. By connecting the edge region of the wound contact layer to the edge region of the covering layer, the receiving space substantially forms the shape of a closed pocket. Connecting the edge regions to each other has the advantage that the connection of the layer disposed in the receiving space to the wound contact layer and / or the covering layer and the connection of the layers disposed in the receiving space to each other can be omitted. Thereby, the process steps involved in connecting these layers can be omitted in the manufacture of the wound dressing, which achieves cost savings.

[0034] Preferably, the edge region of the covering layer and the edge region of the wound contact layer are connected to each other by an adhesive connection or a welding connection. The connection can be implemented in the form of a surface, a line, or a point. The adhesive connection can be performed, for example, by applying an adhesive or by means of a tape. The welding connection can be performed, for example, by heating or by ultrasonic waves.

[0035] According to a preferred embodiment, the covering layer projects laterally beyond the wound contact layer; and at least one section of the covering layer that projects laterally beyond the wound contact layer is designed to be sticky. This enables the wound dressing to be fastened particularly firmly to the skin around the wound. Since the covering layer projects laterally beyond the wound contact layer, in the wound dressing applied as intended, the covering layer only contacts the skin around the wound and does not contact the wound surface. Correspondingly, a highly sticky adhesive can also be used at the section that projects laterally beyond the wound contact layer, and the adhesive should not directly contact the wound surface. According to an alternative embodiment, the covering layer extends at most to the edge of the wound contact layer in the lateral direction but does not extend beyond the edge. Thus, in the wound dressing applied as intended, only the wound contact layer directly contacts the tissue, rather than the covering layer.

[0036] Preferably, a breathable but liquid-impermeable filter unit is provided for the connection opening, and the filter unit functions as a filter between the receiving space and the surrounding environment. Since the filter unit is designed to be breathable, negative pressure can be introduced into the receiving space through the filter unit. Since the filter unit is liquid-impermeable, when the wound dressing is used in negative pressure therapy, the filter unit prevents wound exudate from escaping from the wound dressing. Otherwise, the wound exudate escaping from the wound dressing may contaminate and / or damage the downstream negative pressure source. Preferably, the filter unit is disposed on the side of the covering layer facing the wound contact layer, that is, disposed in the receiving space.

[0037] Preferably, the wound contact layer comprises a perforated film. The perforated film has a plurality of through-holes formed therein, for example, by punching in the film. Correspondingly, wound exudate can be discharged into the receiving space in a manner that is distributed along the wound contact layer. Preferably, the perforated film is a perforated plastic film.

[0038] According to a preferred embodiment, the wound contact layer comprises silicone or hydrogel. Silicone or hydrogel is particularly suitable for forming the wound contact layer. This stems from the fact that silicone and hydrogel generally adhere strongly enough to dry tissue (such as the skin around the wound) to firmly secure the wound dressing. However, silicone and hydrogel adhere only slightly, at most, to moist or wet tissue (such as the wound surface), thus avoiding adhesion to the wound surface. Particularly preferably, the wound contact layer comprises a perforated film, especially a perforated plastic film, which is coated with silicone or hydrogel on its side facing the cover layer.

[0039] Preferably, the wound dressing is packaged as a ready-to-use dressing in an outer package. A ready-to-use dressing is a wound dressing in which the layers are already connected to each other as intended during storage. Such a ready-to-use dressing is not complicated in application.

[0040] The object to be achieved is also achieved by a negative pressure wound therapy kit, which comprises a wound dressing having the above-mentioned features. The negative pressure wound therapy kit according to the invention further comprises a connecting device, which has an elongate single-chamber or multi-chamber connecting hose, the connecting hose comprising a distal end section and a proximal end section, wherein the distal end section can be fluid-connected to the connection opening in a negative pressure-tight manner, and wherein the proximal end section can be fluid-connected to a negative pressure source in a negative pressure-tight manner.

[0041] The terms "distal" and "proximal" describe the arrangement relative to the negative pressure source. The proximal section of a certain element is closer to the negative pressure source than the distal section of the element. In this regard, for example, when the connecting hose is used as intended, the proximal end section of the connecting hose is closer to the negative pressure source than the distal end section.

[0042] Regarding the advantages achievable by the negative pressure wound therapy kit, reference is made to the relevant embodiments of the wound dressing. The features described in connection with the wound dressing can be used to further design the negative pressure wound therapy kit.

[0043] The object to be achieved is also achieved by a negative pressure wound therapy system, which comprises a negative pressure wound therapy kit having the above-mentioned features. The negative pressure wound therapy system according to the invention further comprises a negative pressure source, wherein the proximal end section of the connecting hose can be fluid-connected to the negative pressure source in a negative pressure-tight manner.

[0044] For the advantages achievable by means of a negative pressure wound treatment system, reference is made to the corresponding embodiments of the wound dressing. The features described in connection with the wound dressing can be used for further design of the negative pressure wound treatment system. Description of the Drawings

[0045] In the following, the invention is described in detail with the aid of the drawings, in which identical or functionally identical elements are labeled with the same reference numeral only where necessary. These drawings are given by way of example only and should not be understood as restrictive. In the drawings: Figure 1 A negative pressure wound treatment system with a wound dressing is shown, Figure 2 A sectional view of a first embodiment of the wound dressing is shown, Figure 3 A top view of the distribution layer of the wound dressing is shown, Figure 4 Shown Figure 3 A sectional view of the shown distribution layer along the cutting line A-A is shown, Figure 5 A sectional view of a second embodiment of the wound dressing is shown, Figure 6 A sectional view of a third embodiment of the wound dressing is shown, Figure 7 A sectional view of a fourth embodiment of the wound dressing is shown, and Figure 8 A sectional view of a fifth embodiment of the wound dressing is shown. Detailed Description of the Invention

[0046] Figure 1 A negative pressure wound treatment system 10 for treating wounds by negative pressure is shown. The negative pressure wound treatment system 10 includes a negative pressure source 12 and a negative pressure wound treatment kit 14. The negative pressure wound treatment kit 14 includes a wound dressing 16 and a connecting device 18. The connecting device 18 includes an elongated single-chamber or multi-chamber connecting hose 20 having a proximal end section 22 and a distal end section 24. The proximal end section 22 can be fluid-connected to the negative pressure source 12 in a negative pressure-tight manner. The distal end section 24 can be fluid-connected to a connecting opening 26 in the wound dressing 16 in a negative pressure-tight manner. For this purpose, the distal end section 24 includes a fluid inlet 25. In Figure 1 In the shown negative pressure wound treatment system 10, the distal end section 24 has already been connected to the connecting opening 26, so that the connecting opening 26 is covered by the distal end section 24.

[0047] In the following, reference is also made to Figure 2 to elaborate in detail on the structure of the wound dressing 16. Figure 2Schematic cross-sectional view showing a first embodiment of the wound dressing 16. It should be noted that, for better understanding, the directly superposed layers of the wound dressing 16 are shown spaced apart from each other in Figure 2 In contrast to this illustration, when the wound dressing 16 is in use, the directly superposed layers of the wound dressing 16 are in direct contact.

[0048] The wound dressing 16 includes a wound contact layer 28. The wound contact layer 28 includes a smooth first side 30 for application to the wound surface and a smooth second side 32 facing away from the first side 30.

[0049] Furthermore, the wound dressing 16 includes an airtight covering layer 34 for gas-tightly enclosing the wound. The previously mentioned connection opening 26 is formed in the covering layer 34. Preferably, the covering layer 34 includes a plastic film, especially a polyurethane film. An accommodation space 36 is formed between the wound contact layer 28 and the covering layer 34.

[0050] The wound contact layer 28 is designed to be liquid-permeable for discharging wound exudate from the wound into the accommodation space 36. Here, the wound contact layer 28 includes a plastic film that is coated with silicone or hydrogel on its side facing the wound. The wound contact layer 28 (i.e., the plastic film together with silicone or hydrogel) is designed to be perforated. In this regard, the wound contact layer 28 includes a plurality of perforations or through-holes that are distributed and formed in the wound contact layer 28. Through the perforations, the wound exudate can be discharged from the wound site into the accommodation space 36.

[0051] The wound contact layer 28 includes a central region 38 and an edge region 40 surrounding the central region 38. The covering layer 34 includes a central region 42 and an edge region 44 surrounding the central region 42. Here, the edge region 40 of the wound contact layer 28 is connected to the edge region 44 of the covering layer 34 in a surrounding manner. Correspondingly, the accommodation space 36 is only formed between the central region 38 of the wound contact layer 28 and the central region 42 of the covering layer 34.

[0052] Preferably, the edge regions 40 and 44 are connected to each other by an adhesive connection. For this purpose, particularly preferably, the side of the covering layer 34 facing the wound contact layer 28 is coated with an adhesive, such as an acrylic adhesive, at least in the edge region 44. Alternatively, the edge regions 40 and 44 are connected to each other by a welding connection.

[0053] The connection of the edge regions 40 and 44 holds the additional layers arranged in the accommodation space 36 firmly in the accommodation space 36. Correspondingly, these layers may at most have a slight sliding. The advantage is that the connection of the layers arranged in the accommodation space 36 and the connection of these layers to the wound contact layer 28 and / or to the covering layer 34 can be omitted.

[0054] When the wound dressing 16 is applied to a wound, the distal end portion section 24 is in fluid connection with the connection opening 26 in a negative pressure sealed manner, and the proximal end portion section 22 is in fluid connection with the negative pressure source 12 in a negative pressure sealed manner, a negative pressure can be generated between the covering layer 34 and the wound by the negative pressure source 12 so as to effectively drain wound exudate from the wound.

[0055] In the embodiment shown in the figure, the edge region 44 of the covering layer 34 projects at most to the edge 48 of the wound contact layer 28, but does not project beyond the edge 48. Correspondingly, in the wound dressing 16 applied as expected, the covering layer 34 does not contact the skin around the wound. According to another embodiment, the edge region 44 of the covering layer 34 projects at least partially laterally beyond the edge 48 of the wound contact layer 28. This has the advantage that the wound dressing 16 can be fastened particularly firmly to the tissue. Then, the adhesive on the side of the covering layer 34 facing the wound contact layer 28 comes into contact with the skin around the wound. In Figure 2 This lateral projection of the covering layer 34 is indicated by a dashed line in

[0056] In addition, the wound dressing 16 includes a breathable but liquid-impermeable filter unit 72. The filter unit 72 is assigned to the connection opening 26 and functions as a filter between the receiving space 36 and the surrounding environment. Here, the filter unit 72 is arranged on the side of the covering layer 34 facing the wound contact layer 28.

[0057] In Figure 2 In the first embodiment of the wound dressing 16 shown, a distribution layer 50 is arranged in the receiving space 36. Hereinafter, reference is also made to Figure 3 and Figure 4 to elaborate in detail on the design of the distribution layer 50. For this purpose, Figure 3 a top view of the distribution layer 50 is shown. Figure 4 a cross-sectional view of the distribution layer 50 along the Figure 3 shown cutting line A-A is shown.

[0058] The distribution layer 50 extends in two planar directions X and Y and is designed to distribute wound exudate in the planar directions X and Y. In addition, the distribution layer 50 facilitates the distribution of the generated negative pressure at the wound site. The distribution layer 50 consists of a flat material web section 52. The flat material web section 52 includes a plane 54, which has a first side 56 and a second side 58 facing away from the first side 56.

[0059] The first side 56 of the flat material web section 52 is structured by means of a projection 60 integrally formed in the plane 54. In at least some of the projections 60, end-side through-holes 64 are formed in the protruding end side 62 of the associated projection 60. Here, end-side through-holes 64 are formed in each of the projections 60. A continuous gap 66 is formed between the projections 60 such that wound exudate can be distributed in the gap 66 in the plane directions X and Y. The second side 58 of the flat material web section 52 facing away from the structured first side 56 is designed to be smooth.

[0060] Preferably, the projection density of the first side 56 of the flat material web section 52 is at least 200 projections per cm2 to at most 400 projections 60 per cm2. Here, the projection density is 280 projections 60 per cm2. Preferably, the diameter of the end-side through-holes 64 is at least 200 µm and at most 500 µm.

[0061] In order to form the continuous gap 66, the projections 60 are arranged isolated from one another in an island-like manner. In the illustrated embodiment, the projections 60 are shaped like a hyperboloid of one sheet. Here, the projections 60 are thus designed to be hyperbolic. For this purpose, the covering walls of the projections 60 are reciprocally curved. Alternatively, the projections 60 are preferably designed to be conical (i.e., frustoconical), cylindrical or truncated conical.

[0062] The projections 60 are preferably distributed in such a way that at least in the central region of the flat material web section 52, each of the projections 60 is surrounded by three to eight further projections 60, where the further projections 60 together form a regular polygon. Here, these further projections 60 together form a regular hexagon. That is, at least in the central region of the flat material web section 52, each of the projections 60 is surrounded by six further projections 60. Arranging the projections 60 in this way enables a particularly uniform distribution of the wound exudate in the plane directions X and Y.

[0063] Here, the flat material web section 52 is a plastic film 52. Preferably, the plastic film 52 is made of polyethylene, polyurethane, polyvinyl chloride or a mixture thereof. These plastics have the advantage that on the one hand a flexible deformable distribution layer 50 can be obtained. The resulting wound dressing 16 has a favorable drapability. In addition, the above-mentioned plastics also have sufficient rigidity. In this regard, these plastics ensure that during use of the wound dressing 16, despite the generation of a negative pressure, the continuous gap 66 can still be maintained.

[0064] The projection 60 is produced by means of vacuum deep drawing. Preferably, for this purpose, a flat material web (in particular a plastic film web) that has been extruded or calendered and is still in a molten state is guided onto a rotating, perforated negative pressure roller. Then, the flat material web is locally sucked into the holes of the vacuum perforation roller by the negative pressure in the perforated negative pressure roller, thereby forming the projection 60. Here, the shape of the obtained projection 60 is determined, for example, by the contour of the holes and the negative pressure used. Preferably, the negative pressure in the perforated negative pressure roller is adjusted such that the end side 62 of the projection 60 is opened. Thus, the projection 60 and the through-hole 64 are formed in the same process step.

[0065] The distribution layer 50 is arranged in the receiving space 36 in such a way that the projection 60 projects in the direction towards the covering layer 34. This helps to convey wound exudate through the distribution layer 50 in the direction towards the covering layer 34. Specifically, in the projection 60, capillary forces act on the wound exudate, which is conducive to the conveyance in the direction towards the covering layer 34.

[0066] In Figures 5 to 8 different further embodiments of the wound dressing 16 are schematically shown. In Figures 5 to 8 the embodiment disclosed in Figure 2 differs from the embodiment shown in Figures 5 to 8 in the layers arranged in the receiving space 36. With regard to the design of the wound contact layer 28, the covering layer 34, and the distribution layer 50 present, reference is made to the previous explanations for these layers. The wound dressing 16 shown in Figures 5 to 8 can also be present as a wound dressing in a negative pressure wound treatment kit 14 or a negative pressure wound treatment system 10.

[0067] Figure 5 A cross-sectional view showing a second embodiment of the wound dressing 16 is shown. In Figure 5 the wound dressing 16 shown, the distribution layer 50 and the absorbent layer 70 are arranged in the receiving space 36.

[0068] The absorbent layer 70 is designed to receive wound exudate and store the received wound exudate. For forming the absorbent layer 70, various particularly hydrophilic materials are considered. Preferably, the absorbent layer 70 comprises superabsorbent polymers, superabsorbent fibers, cellulose, and / or hydrophilic nonwoven materials.

[0069] The distribution layer 50 and the absorption layer 70 are arranged directly on top of each other 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 protrusions 60 of the distribution layer 50 face towards the absorption layer 70. By means of the lateral distribution of wound exudate in the gaps 66, it is achieved that most of the surface area of the absorption layer 70 is used for receiving the wound exudate. Thereby, clogging of the absorption layer 70 is prevented. Such clogging is more likely to occur in cases where the wound exudate is only received by the absorption layer 70 at certain isolated sites.

[0070] Figure 6 Cross-sectional view showing a third embodiment of the wound dressing 16. In Figure 5 the wound dressing 16 shown, a first distribution layer 50-1 and a second distribution layer 50-2 are arranged in the receiving space 36.

[0071] The first distribution layer 50-1 and the second distribution layer 50-2 are arranged on top of each other in the receiving space 36 in such a way that the protrusions 60 of the distribution layers 50-1 and 50-2 protrude in the same direction, here in the direction towards the cover layer 34. Thereby, capillary forces act in the protrusions 60 of the first distribution layer 50-1 as well as in the protrusions 60 of the second distribution layer 50-2 in the direction towards 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.

[0072] Figure 7 Cross-sectional view showing a fourth embodiment of the wound dressing 16. In Figure 7 the wound dressing 16 shown, a first distribution layer 50-1, a second distribution layer 50-2 and an absorption layer 70 are arranged in the receiving space 36.

[0073] The distribution layers 50-1 and 50-2 are arranged on different sides of the absorption layer 70 respectively. 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 protrusions 60 protrude in the same direction, here in the direction towards the cover layer 34. The second distribution layer 50-2 prevents certain areas of the absorption layer 70 from being isolated from the negative pressure. Such isolation of certain areas may impair the efficiency of the wound dressing 16 in discharging wound exudate from the wound.

[0074] Figure 8 Cross-sectional view showing a fifth embodiment of the wound dressing 16. In Figure 8 the wound dressing 16 shown, 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.

[0075] The second distribution layer 50-2 is disposed between the first absorbent layer 70-1 and the second absorbent layer 70-2. The first distribution layer 50-1 is disposed on a side of the first absorbent layer 70-1 facing away from the second absorbent layer 70-2. The third distribution layer 50-3 is disposed on a side of the second absorbent layer 70-2 facing away from the first absorbent layer 70-1. The distribution layers 50-1, 50-2 and 50-3 are disposed in the receiving space 36 in such a way that their protrusions 60 protrude in the same direction, here in the direction towards the cover layer 34.

Claims

1. A wound dressing (16) for negative pressure treatment of wounds, the wound dressing having: A wound contact layer (28) for application to a wound surface, wherein, The wound contact layer (28) includes a smooth first side (30) and a smooth second side (32) facing away from the first side (30); An airtight covering layer (34) for gas-tightly enclosing the wound, wherein An accommodation space (36) is formed between the covering layer (34) and the wound contact layer (28), wherein The wound contact layer (28) is designed to be liquid-permeable for discharging wound exudate from the wound into the accommodation space (36), and wherein A connection opening (26) is formed in the covering layer (34) for establishing a negative pressure-sealed fluid connection between the accommodation space (36) and a negative pressure source (12); and At least one distribution layer (50) disposed in the accommodation space (36), wherein the distribution layer (50) extends in two planar directions (X, Y) and is designed to distribute wound exudate in the planar directions (X, Y), characterized in that The distribution layer (50) is composed of a flat material web section (52); The first side (56) of the flat material web section (52) is structurally designed by protrusions (60) integrally formed in the plane (54) of the flat material web section (52); End-side through-holes (64) are formed in at least some of the protrusions (60), especially in all of the protrusions (60); and A continuous gap (66) is formed between the protrusions (60) such that wound exudate can be distributed in the gap (66) in the planar directions (X, Y).

2. The wound dressing (16) according to claim 1, characterized in that, The protrusions (60) are designed to be conical, cylindrical, frustoconical or hyperbolic.

3. The wound dressing (16) according to one of claims 1 and 2, characterized in that, At least in the central region of the flat material web section (52), each of the protrusions (60) is surrounded by three to eight other protrusions (60), wherein the other protrusions (60) together form a regular polygon, especially a regular hexagon.

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

5. The wound dressing (16) according to one of claims 1 to 4, characterized in that, The protrusions (60) are formed by vacuum deep drawing.

6. The wound dressing (16) according to any one of claims 1 to 5, characterized in that, The flat material web section (52) is made of polyethylene, polyurethane, polyvinyl chloride or a mixture thereof.

7. The wound dressing (16) according to one of claims 1 to 6, characterized in that, The distribution layer (50) is disposed in the accommodation space (36) such that the protrusions (60) project in the direction towards the covering layer (34).

8. The wound dressing (16) according to any one of claims 1 to 7, characterized in that, At least one additional distribution layer (50) is arranged in the receiving space (36), the additional distribution layer extending in two planar directions (X, Y) and being designed to distribute wound exudate in the planar directions (X, Y); the additional distribution layer (50) is composed of a flat material web section (52); a first side (56) of the flat material web section (52) is structurally designed by means of projections (60) integrally formed in a plane (54) of the flat material web section (52); end-side through-holes (64) are formed in at least some of the projections (60), in particular in all of the projections (60); continuous gaps (66) are formed between the projections (64) such that wound exudate can be distributed in the gaps (66) in the planar directions (X, Y); and the distribution layer (50) and the additional distribution layer (50) are arranged one above the other.

9. The wound dressing (16) according to claim 8, characterized in that, The distribution layer (50) and the additional distribution layer (50) are arranged such that the projections of the distribution layer (50) project in the same direction.

10. The wound dressing (16) according to any one of claims 1 to 9, characterized in that, At least one absorbent layer (70) is arranged in the receiving space (36), the absorbent layer being designed to receive wound exudate and store the received wound exudate.

11. The 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 absorbent layer (70) and the wound contact layer (28).

12. The 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 absorbent layer (70) and the cover layer (34).

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

14. The wound dressing (16) according to one of claims 10 to 13, characterized in that, At least one additional absorbent layer (70) is arranged in the receiving space (36), the additional absorbent layer being designed to receive wound exudate and store the received wound exudate; and the absorbent layer (70) and the additional absorbent layer (70) are arranged one above the other.

15. The 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 absorbent layer (70) and the additional absorbent layer (70).

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

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

18. The wound dressing (16) according to any one of claims 1 to 17, characterized in that, The connection opening (26) is provided with a breathable but liquid-impermeable filter unit (72), which filters between the receiving space (36) and the surrounding environment.

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

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

21. The wound dressing (16) according to any one of claims 1 to 20, characterized in that, The wound dressing is packaged as a ready-to-use dressing in an outer package.

22. A negative pressure wound treatment kit (14), the negative pressure wound treatment kit having a wound dressing (16) according to one of claims 1 to 21 and a connection device (18), the connection device comprising an elongate single-chamber or multi-chamber connection hose (20), the connection hose having a distal end section (24) and a proximal end section (22), wherein the distal end section (24) is capable of being in fluid connection with the connection opening (26) in a negative pressure-tight manner, and wherein the proximal end section (22) is capable of being in fluid connection with a negative pressure source (12) in a negative pressure-tight manner.

23. A negative pressure wound treatment system (10), the negative pressure wound treatment system having the negative pressure wound treatment kit (14) according to claim 22 and a negative pressure source (12), wherein the proximal end section (22) of the connection hose (20) is capable of being in fluid connection with the negative pressure source (12) in a negative pressure-tight manner.

Images