CN114569330A - Wound dressing and negative pressure wound therapy device - Google Patents

Abstract

The present application provides a wound dressing and a negative pressure wound therapy device. Wherein the wound dressing comprises a backing layer, an absorbent pouch, an absorbent layer, and at least one pressure distribution layer. Wherein the backing layer is provided with an opening for fluid communication with a negative pressure source; the absorption bag is arranged on one side of the back lining layer and comprises a first structural layer and a second structural layer, the peripheries of the second structural layer and the first structural layer are jointed to form a containing space, and the first structural layer is closer to the back lining layer than the second structural layer; the absorption layer is arranged in the accommodating space; the at least one pressure distribution layer and the absorption bag are arranged on the same side of the backing layer, and the pressure distribution layer is positioned on one side of the absorption layer close to the backing layer and/or one side of the absorption layer far away from the backing layer; the softness of the first structural layer is greater than that of the pressure distribution layer, and the softness of the second structural layer is greater than that of the pressure distribution layer. The technical scheme that this application provided can prevent absorbing layer local jam to a certain extent.

Description

Wound dressing and negative pressure wound therapy device

Technical Field

The application relates to the technical field of medical equipment, in particular to a wound dressing and a negative pressure wound treatment device.

Background

Negative pressure wound therapy applies negative pressure to a wound by using a negative pressure source, can accelerate blood circulation of a wound part and stimulate the growth of granulation tissue, thereby being beneficial to promoting wound healing, and is a pure physical therapy developed in recent years for wound treatment.

Related art wound dressings for negative pressure wound therapy generally include a backing layer, an absorbent layer, and a wound contact layer, which are sequentially disposed in a stack. The backing layer is provided with an opening to communicate with a source of negative pressure. In the process of applying negative pressure, the negative pressure is often easily concentrated on the position corresponding to the opening of the backing layer, so that wound exudate is concentrated on the position of the absorption layer corresponding to the opening of the backing layer, local blockage of the absorption layer is easily caused, the absorption layer cannot continuously transmit the negative pressure, and finally, the wound part cannot be continuously and effectively treated by the negative pressure.

Disclosure of Invention

The application provides a wound dressing and negative pressure wound treatment device to solve the technical problem that the absorption layer takes place to block up easily.

A wound dressing for negative pressure therapy includes a backing layer, an absorbent pouch, an absorbent layer, and at least one pressure distribution layer. Wherein the backing layer is provided with an opening for fluid communication with a negative pressure source; the absorption bag is arranged on one side of the back lining layer and comprises a first structural layer and a second structural layer, the peripheries of the second structural layer and the first structural layer are jointed to form a containing space, and the first structural layer is closer to the back lining layer than the second structural layer; the absorption layer is arranged in the accommodating space; the at least one pressure distribution layer and the absorption bag are arranged on the same side of the backing layer, and the pressure distribution layer is positioned on one side of the absorption layer close to the backing layer and/or one side of the absorption layer far away from the backing layer; the softness of the first structural layer is greater than that of the pressure distribution layer, and the softness of the second structural layer is greater than that of the pressure distribution layer.

On the one hand, this application sets up pressure distribution layer through the one side that deviates from the backing layer in one side of the one side that is close to the backing layer of absorbent layer and/or absorbent layer, and pressure distribution layer can play the effect of distribution negative pressure to make wound exudate evenly distributed on the absorbent layer, thereby be favorable to avoiding absorbent layer local blocking. On the other hand, through setting up the absorption bag in this application for the absorbent layer is located the absorbent bag, and the fibre or the granule that drops from the absorbent layer are kept in the absorbent bag, and can not drop on the wound position, thereby form the protection to the wound position.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural view of a first embodiment of a wound dressing according to the related art;

FIG. 2 is a schematic cross-sectional view of the wound dressing of FIG. 1 taken along line A-A;

FIG. 3 is a schematic cross-sectional view of a first embodiment of a wound dressing according to the present application;

FIG. 4 is a schematic cross-sectional view of a second embodiment of a wound dressing according to the present application;

FIG. 5 is a schematic cross-sectional view of a wound dressing according to a third embodiment of the present invention

FIG. 6 is a schematic cross-sectional view of a fourth embodiment of a wound dressing according to the present application;

FIG. 7 is a schematic cross-sectional view of a second embodiment of a wound dressing according to the related art;

FIG. 8 is a schematic cross-sectional view of a third embodiment of a wound dressing according to the related art;

FIG. 9 is a schematic illustration of a fit test of the present application;

fig. 10 is a schematic structural diagram of an embodiment of the negative pressure wound therapy device of the present application.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples. It is to be noted that the following examples are only illustrative of the present application, and do not limit the scope of the present application. Likewise, the following examples are only some examples and not all examples of the present application, and all other examples obtained by a person of ordinary skill in the art without any inventive work are within the scope of the present application.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

First, an embodiment of a wound dressing in the related art will be described.

< first embodiment of the related art >

Referring to fig. 1 and 2, thewound dressing 10 includes a backing layer 1, a water-blocking andbreathable film 2, apressure distribution layer 4, anabsorption layer 5, atransmission layer 6, awound contact layer 7, and arelease film layer 8, which are sequentially stacked.

First, the overall structure of thewound dressing 10 will be described.

The backing layer 1 is jointed with the periphery of thewound contact layer 7 to form a containing space. The water-blockingbreathable film 2, thepressure distribution layer 4, theabsorption layer 5 and thetransmission layer 6 are positioned in the accommodating space. Wherein, the water-proofbreathable film 2 is attached to the lower surface of the back lining layer 1. Thepressure distribution layer 4 and thetransmission layer 6 are of the same or approximately the same size, i.e. the orthographic projection of thepressure distribution layer 4 in the plane of the backing layer 1 and the orthographic projection of thetransmission layer 6 in the plane of the backing layer 1 are exactly coincident. It should be noted that the perfect registration described in this application allows a certain margin of error, for example, as long as the orthographic projection of thepressure distribution layer 4 on the plane of the backing layer 1 and the orthographic projection of thetransmission layer 6 on the plane of the backing layer 1 are 90% registered, it is understood that perfect registration is possible.

Thepressure distribution layer 4 and thetransmission layer 6 are jointed to form a containing space, and theabsorption layer 5 is positioned in the containing space.Release film layer 8 is tearable, when usingwound dressing 10, can tearrelease film layer 8, withwound contact layer 7 and wound position direct contact.

Next, the material of each layer will be described.

The backing layer 1 is provided with an opening 1a, and thewound dressing 10 is in communication with a source of negative pressure through the opening 1a in the backing layer 1. The water-blockingbreathable film 2 covers the opening 1a in the backing layer 1. The water-resistant, gas-permeable membrane 2 allows gas to pass through, but not liquid to avoid wound exudate in thewound dressing 10 from entering the negative pressure source.

Thepressure distribution layer 4 allows both gas and liquid to pass through. Thepressure distribution layer 4 is a material with a three-dimensional structure and has relatively low softness. Thepressure distribution layer 4 serves to distribute the negative pressure to the side of theabsorbent layer 5 facing thepressure distribution layer 4, so that wound exudate is evenly distributed over theabsorbent layer 5, which is advantageous for avoiding partial blocking of theabsorbent layer 5. The term "material having a three-dimensional structure" as used herein refers to a material having a porous structure (including macroscopic pores and gaps and microscopic pores and gaps), allowing fluid to flow therethrough, and functioning to distribute negative pressure, such as foam, dacron mesh, and hot-air cotton.

Theabsorbent layer 5 is used to absorb and store wound exudate. Thetransfer layer 6 allows both gas and liquid to pass through. Thetransmission layer 6 is made of a material with a three-dimensional structure, and the softness is relatively small. Thetransmission layer 6 distributes negative pressure to one side of theabsorption layer 5 facing thetransmission layer 6, so that wound exudate is uniformly distributed on theabsorption layer 5, and partial blockage of theabsorption layer 5 is avoided.

The thickness of thepressure distribution layer 4, theabsorbent layer 5 and thetransmission layer 6 is relatively large throughout thewound dressing 10 as a whole, and thus the fit of thewound dressing 10 is mainly affected by the three of thepressure distribution layer 4, theabsorbent layer 5 and thetransmission layer 6.

Thepressure distribution layer 4 and thetransmission layer 6 are both made of materials with three-dimensional structures, and the softness is smaller, and the softness of the joint of thetransmission layer 6 and thepressure distribution layer 4 becomes smaller, so that thewhole wound dressing 10 is relatively poor in fitting property.

Next, the wound dressing of the present application will be described in detail.

< first embodiment of the present application >

Referring to fig. 3, in the present embodiment, thewound dressing 10 includes a backing layer 1, a water-blockingbreathable film 2, a sealing layer 3 (in the present embodiment, it may also be referred to as a first structural layer), apressure distribution layer 4, anabsorption layer 5, a transmission layer 6 (in the present embodiment, it may also be referred to as a second structural layer), awound contact layer 7, and arelease film layer 8, which are sequentially stacked.

First, the overall structure of thewound dressing 10 will be described. The backing layer 1 is jointed with the periphery of thewound contact layer 7 to form a containing space. The water-blockingbreathable film 2, thesealing layer 3, thepressure distribution layer 4, theabsorption layer 5 and thetransmission layer 6 are positioned in the accommodating space. Wherein, the water-proofbreathable film 2 is attached to the lower surface of the back lining layer 1. Theenclosing layer 3 and thetransmission layer 6 are jointed at the periphery to form an accommodating space, and thepressure distribution layer 4 and theabsorption layer 5 are positioned in the accommodating space.Release film layer 8 is tearable, when using wound dressing 10, can tearrelease film layer 8, withwound contact layer 7 and wound position direct contact.

Next, the backing layer 1, the water-and air-permeable membrane 2, thesealing layer 3, thepressure distribution layer 4, theabsorbent layer 5, thetransmission layer 6, and thewound contact layer 7 will be described in detail one by one.

The backing layer 1 may be permeable to moisture. The wound exudate in theabsorbent layer 5 evaporates to form moisture which can diffuse out through the backing layer 1, resulting in a wound dressing 10 with good breathability. The backing layer 1 may be, for example, a transparent polyurethane film, and may have a thickness of between 0.05mm and 0.15 mm. The backing layer 1 may also be air impermeable.

The lower surface of the backing layer 1 may be provided with an adhesive, which may be, for example, a polyacrylic adhesive. In this embodiment, the adhesive can be formed by spot application, i.e. the adhesive is arranged in spots and is evenly distributed over the entire lower surface of the backing layer 1. Moisture formed by evaporation of wound exudate in theabsorbent layer 5 can diffuse out through the gaps between the spots. That is, the adhesive disposed in dots is advantageous in improving the air permeability of the wound dressing 10.

In some embodiments, the adhesive may be distributed only in the peripheral regions of the backing layer 1, that is, the middle region of the backing layer 1 may be free of adhesive. In some embodiments, the adhesive may also be formed by knife coating, i.e., the adhesive is continuously disposed and does not allow moisture to permeate.

The backing layer 1 is provided with an opening 1a, and the wound dressing 10 is in communication with a source of negative pressure through the opening 1a in the backing layer 1. In this embodiment, the opening 1a may be a circular hole, and certainly, in some embodiments, the opening 1a may also be a square hole, a hexagonal hole, or a hole with other irregular shapes.

The water-blockingbreathable film 2 covers the opening 1a of the backing layer 1, that is, the orthographic projection of the opening 1a on the plane of the water-blockingbreathable film 2 falls completely on the water-blockingbreathable film 2. As shown in fig. 2, the water-blocking air-permeable film 2 has a size slightly larger than that of the opening 1 a. The water-resistant, gas-permeable membrane 2 allows gas to pass through, but not liquid to avoid wound exudate in the wound dressing 10 from entering the negative pressure source. For example, the water-blocking and air-permeable membrane 2 may be a polytetrafluoroethylene film, which is not limited in this application and can be selected by those skilled in the art according to actual needs. As described above, in the present embodiment, the water-and air-permeable film 2 is adhered to the lower surface of the backing layer 1. In some embodiments, the water-andbreathable film 2 may also be adhered to the upper surface of the backing layer 1.

Theclosing layer 3 allows both gas and liquid to pass through. In this embodiment, thesealing layer 3 may be a polypropylene nonwoven fabric, and the softness of the polypropylene nonwoven fabric is relatively large. The thickness of the sealing layer is between 0.05mm and 0.2 mm. In some embodiments, thesealing layer 3 may also be made of polyester fabric, nylon fabric, or other materials with high softness.

Thepressure distribution layer 4 allows both gas and liquid to pass through. Thepressure distribution layer 4 may in particular be a dacron mesh cloth, and may have a thickness of between 1mm and 2 mm. The terylene mesh cloth is a material with smaller softness, the softness of the terylene mesh cloth is smaller than that of the polypropylene non-woven fabric, and thepressure distribution layer 4 is relatively thicker, so that the softness of thepressure distribution layer 4 is relatively smaller, and the softness of thesealing layer 3 is larger than that of thepressure distribution layer 4.

Thepressure distribution layer 4 distributes the negative pressure over theabsorbent layer 5 so that wound exudate is evenly distributed over theabsorbent layer 5, which is advantageous in avoiding local clogging of theabsorbent layer 5. In some embodiments, the material of thepressure distribution layer 4 may also be other materials with a three-dimensional structure, such as foam, hot-air cotton, etc., which is not limited in this application and can be selected by one skilled in the art according to actual needs.

Theabsorbent layer 5 is used to absorb and store wound exudate. For example, theAbsorbent layer 5 may comprise cellulose and SAP (Super Absorbent Polymer) particles, wherein the content (by weight) of the SAP particles is between 30% and 80%. The higher the content of SAP-particles, the higher the ability of theabsorbent layer 5 to absorb wound exudate and the poorer the air permeability. The thickness of theabsorption layer 5 may be between 1.5mm and 2.5 mm.

Thetransfer layer 6 allows both gas and liquid to pass through. Thetransmission layer 6 distributes the negative pressure below theabsorption layer 5, so that the wound exudate is evenly distributed on theabsorption layer 5, thereby being beneficial to avoiding the local blockage of theabsorption layer 5. For example, thetransfer layer 6 may be a hot air cotton with a thickness of 0.3mm to 0.8 mm. The softness of the hot-air cotton is greater than that of the terylene mesh cloth under the condition of the same thickness; and the thickness of thetransfer layer 6 is smaller than the thickness of thepressure distribution layer 4, whereby the softness of thetransfer layer 6 is greater than the softness of thepressure distribution layer 4. Thetransfer layer 6 is inferior to thepressure distribution layer 4 in terms of its ability to distribute negative pressure.

The dimensions of thetransmission layer 6 may be the same or approximately the same as the dimensions of theclosing layer 3, i.e. the orthographic projection of thetransmission layer 6 onto the plane of the backing layer 1 coincides exactly with the orthographic projection of theclosing layer 3 onto the plane of the backing layer 1. It should be noted that the perfect registration described in this application allows a certain margin of error, for example, as long as the orthographic projection of thetransmission layer 6 on the plane of the backing layer 1 and the orthographic projection of thesealing layer 3 on the plane of the backing layer 1 are 90% coincident, it can be understood as perfect registration.

Thetransmission layer 6 is bonded to the periphery of thesealing layer 3, specifically, ultrasonic welding can be adopted to form an absorption bag, an accommodating space is formed in the absorption bag, and thepressure distribution layer 4 and theabsorption layer 5 are arranged in the accommodating space. The fibers or particles falling from theabsorbent layer 5 are retained in the housing space and do not fall onto the wound site, thereby providing protection to the wound site.

In some embodiments, thetransfer layer 6 and thepressure distribution layer 4 may also be bonded all around. When thetransfer layer 6 is bonded to thepressure distribution layer 4, there is a risk of bond failure after theabsorbent layer 5 has absorbed a significant amount of wound exudate, ultrasonic welding being more secure than bonding.

The dimensions of thewound contact layer 7 may be the same or substantially the same as the dimensions of the backing layer 1. Specifically, in this embodiment, thewound contact layer 7 and the backing layer 1 are both rectangular, the length of thewound contact layer 7 is the same or substantially the same as the length of the backing layer 1, and the width of thewound contact layer 7 is the same or substantially the same as the width of the backing layer 1. The thickness of thewound contact layer 7 may be between 0.05mm and 0.2 mm. Thewound contact layer 7 may comprise a layer of silicone gel to avoid scar tissue proliferation. The silicone gel layer may be provided with a plurality of through holes through which liquid and gas are transferred.

Compared with the related art, the embodiment has the advantages that theenclosing layer 3 with high softness is added, theenclosing layer 3 replaces thepressure distribution layer 4 with low softness to be peripherally jointed with thetransmission layer 6 to form the absorption bag, the softness of the joint is reduced to a large extent, the whole dressing is better in fitting performance, and therefore the dressing can be applied to the bent parts of knees, elbows and the like.

Further, the size of thepressure distribution layer 4 is smaller than the size of theabsorption layer 5. That is to say that the orthographic projection of thepressure distribution layer 4 onto the plane of theabsorption layer 5 is entirely located on theabsorption layer 5. When the wound dressing 10 is applied to a wound, thetransmission layer 6, theabsorption layer 5 and thepressure distribution layer 4 are sequentially superposed on the wound site, and the sizes of thetransmission layer 6, theabsorption layer 5 and thepressure distribution layer 4 are sequentially reduced, so that the fitting performance of the wound dressing 10 is further improved.

< example two of the present application >

Referring to fig. 4, in the present embodiment, the wound dressing 10 includes a backing layer 1, a water-blockingbreathable film 2, apressure distribution layer 4, a sealing layer 3 (in the present embodiment, may also be referred to as a first structural layer), anabsorption layer 5, a transmission layer 6 (in the present embodiment, may also be referred to as a second structural layer), awound contact layer 7, and arelease film layer 8, which are sequentially stacked.

The present embodiment is different from the first embodiment of the present application in that: the peripheries of thesealing layer 3 and thetransmission layer 6 are jointed to form an accommodating space, theabsorption layer 5 is positioned in the accommodating space, and thepressure distribution layer 4 is positioned outside the accommodating space; thepressure distribution layer 4 is located between theclosing layer 3 and the backing layer 1.

The remaining features of the backing layer 1, the water-blockingbreathable film 2, thesealing layer 3, thepressure distribution layer 4, theabsorption layer 5, thetransmission layer 6, thewound contact layer 7, and therelease film layer 8 may be the same as or similar to those of the first embodiment of the present application, and are not described herein again.

< third embodiment of the present application >

Referring to fig. 5, in the present embodiment, the wound dressing 10 includes a backing layer 1, a water-blockingbreathable film 2, a transmission layer 6 (in the present embodiment, it may also be referred to as a first structural layer), anabsorption layer 5, apressure distribution layer 4, a sealing layer 3 (in the present embodiment, it may also be referred to as a second structural layer), awound contact layer 7, and arelease film layer 8, which are sequentially stacked.

The present embodiment is different from the first embodiment of the present application in that: the peripheries of thesealing layer 3 and thetransmission layer 6 are jointed to form an accommodating space, theabsorption layer 5 and thepressure distribution layer 4 are positioned in the accommodating space, the positions of thesealing layer 3 and thetransmission layer 6 are interchanged, thesealing layer 3 is positioned on one side of theabsorption layer 5 facing thewound contact layer 7, and thetransmission layer 6 is positioned on one side of theabsorption layer 5 facing the back lining layer 1; thepressure distribution layer 4 is positioned on the side of theabsorbent layer 5 facing thewound contact layer 3, so that thepressure distribution layer 4 and thetransmission layer 6 distribute negative pressure on both sides of theabsorbent layer 5; thepressure distribution layer 4 is the same or approximately the same size as theabsorbent layer 5, i.e. the orthographic projection of thepressure distribution layer 4 onto the plane of the backing layer 1 coincides exactly with the orthographic projection of theabsorbent layer 5 onto the plane of the backing layer 1.

It should be noted that the perfect registration described in this application allows a certain margin of error, for example, as long as the orthographic projection of thepressure distribution layer 4 on the plane of the backing layer 1 and the orthographic projection of theabsorbent layer 5 on the plane of the backing layer 1 are 90% registered, it is understood that perfect registration is possible.

In this embodiment thepressure distribution layer 4 distributes the negative pressure below theabsorbent layer 5 and thetransfer layer 6 distributes the negative pressure above theabsorbent layer 5. The wound dressing in the first example of the present application is better than the wound dressing in the present example in terms of the effect of preventing partial blocking of theabsorbent layer 5.

In terms of air permeability, in the first embodiment of the present application, the pressure distribution layer 4 (the material is the dacron mesh fabric) and the sealing layer 3 (the material is the polypropylene non-woven fabric) above theabsorption layer 5 are both made of materials with good moisture permeability, which is beneficial to the moisture formed by the evaporation of the wound exudate in theabsorption layer 5 to diffuse upwards and diffuse out through the backing layer 1. In this embodiment, the material of thetransmission layer 6 located above theabsorption layer 5 is hot air cotton, and the moisture permeability of the hot air cotton is relatively poor, so that the air permeability of the wound dressing in the first embodiment of the present application is better than that of the wound dressing in this embodiment.

In this embodiment, the size of thepressure distribution layer 4 is comparable to the size of theabsorbent layer 5, and to the size of theabsorbent layer 5 in the first embodiment of the present application. That is, the size of the pressure distribution layer in this embodiment is larger than in the first embodiment of the present application. Because the thickness ofpressure distribution layer 4 is great, and this application compliance is relatively poor of material, consequently, regarding the laminating nature, the wound dressing in this application embodiment one compares wound dressing in this embodiment to some better.

< example four of the present application >

Referring to fig. 6, in the present embodiment, the wound dressing 10 includes a backing layer 1, a water-blocking andbreathable film 2, a first sealing layer 3 (in the present embodiment, it may also be referred to as a first structural layer), apressure distribution layer 4, anabsorption layer 5, a second sealing layer 3' (in the present embodiment, it may also be referred to as a second structural layer), a transmission layer 6 (thetransmission layer 6 may also function to distribute negative pressure, in the present embodiment, thetransmission layer 6 may also be regarded as another pressure distribution layer), awound contact layer 7, and arelease film layer 8, which are sequentially stacked.

The present embodiment is different from the first embodiment of the present application in that: the wound dressing 10 includes two occlusive layers: a first and asecond sealing layer 3, 3'; thefirst sealing layer 3 and the second sealing layer 3' have the same or approximately the same size and are jointed at the periphery, specifically, ultrasonic welding can be adopted to form an accommodating space, and thepressure distribution layer 4 and theabsorption layer 5 are positioned in the accommodating space; thetransmission layer 6 is located between the second closing layer 3' and thewound contact layer 7.

Wherein thefirst closing layer 3 allows both gas and liquid to pass through. In the present embodiment, thefirst sealing layer 3 may be a polypropylene nonwoven fabric with a thickness of 0.05mm to 0.2 mm. In some embodiments, thefirst sealing layer 3 may also be made of a material with high softness, such as polyester fabric, nylon fabric, or the like.

The second closing layer 3' allows both gas and liquid to pass through. In this embodiment, the second sealing layer 3' may be a polypropylene nonwoven fabric with a thickness of 0.05mm to 0.2 mm. In some embodiments, the second sealing layer 3' may also be made of a material with high softness, such as polyester fabric, nylon fabric, or the like.

The remaining features of the backing layer 1, the water-blockingbreathable film 2, thepressure distribution layer 4, theabsorbent layer 5, thetransmission layer 6, thewound contact layer 7, and therelease film layer 8 may be the same as or similar to those of the first embodiment of the present application, and are not described herein again.

In this embodiment thepressure distribution layer 4 and thetransfer layer 6 distribute negative pressure on both sides of theabsorbent layer 5, respectively. The effect of preventing partial blocking of theabsorbent layer 5 is comparable to the wound dressing 10 of the first embodiment of the present application.

In terms of fit and air permeability, the wound dressing 10 of the first embodiment of the present invention includes only onesealing layer 3, and the wound dressing of the first embodiment of the present invention includes two sealing layers, so that the fit and air permeability of the wound dressing of the first embodiment of the present invention are better than those of the wound dressing of the first embodiment of the present invention.

On the other hand, the present application also studies the anti-blocking effect of the first to fourth embodiments of the present application and the first to third embodiments of the related art.

The first related art embodiment has been described in detail, and is not repeated herein.

< related art example two >

Referring to fig. 7, the wound dressing 10 includes a backing layer 1, a water-blockingbreathable film 2, anabsorbent layer 5, apressure distribution layer 4, awound contact layer 7, and arelease film layer 8, which are sequentially stacked. Wherein the backing layer 1 is configured to form a seal at a wound site, the backing layer 1 comprising an opening 1 a. Theabsorbent layer 5 is used to absorb wound exudate. Thepressure distribution layer 4 serves to transport wound exudate and to distribute negative pressure from a negative pressure source. Thewound contact layer 7 is intended to be in direct contact with the wound in use. Arelease film layer 8 is removably attached to thewound contact layer 7. In this embodiment thepressure distribution layer 4 has the same or approximately the same size as theabsorbent layer 5.

< third embodiment of the related art >

Referring to fig. 8, the wound dressing 10 includes a backing layer 1, a water-blockingbreathable film 2, anabsorbent layer 5, apressure distribution layer 4, awound contact layer 7, and arelease film layer 8, which are sequentially stacked. Wherein the backing layer 1 is configured to form a seal at a wound site, the backing layer 1 comprising an opening 1 a. Theabsorption layer 5 is used for absorbing wound exudate, and theabsorption layer 5 is perforated, and the perforated position corresponds to the opening 1a of the backing layer 1. Thepressure distribution layer 4 serves to transport wound exudate and to distribute negative pressure from a negative pressure source. Thewound contact layer 7 is intended to be in direct contact with a wound in use. Arelease film layer 8 is removably attached to thewound contact layer 7. In this embodiment thepressure distribution layer 4 has the same or approximately the same size as theabsorbent layer 5.

In the above-described first to fourth embodiments of the present application and first to third embodiments of the related art, the backing layer 1, theabsorbent layer 5, and thewound contact layer 7 have the same or substantially the same size. In the first to fourth embodiments of the present application and the first related art described above, the sizes of thetransmission layer 6 are substantially the same. In the first to fourth embodiments of the present application described above, thesealing layer 3 has substantially the same size.

Next, the test results of the anti-clogging test performed on the first to fourth embodiments of the present application and the first to third embodiments of the related art will be described.

Specifically, a wound dressing 10 of consistent gauge was applied to the test apparatus, a negative pressure of 80 ± 5mmHg was applied to the wound dressing 10, while a 0.9% sodium chloride solution was injected at a constant rate of 21g/day into the wound dressing 10, while the negative pressure at thewound contact layer 7 of the dressing was continuously monitored and the time at which the negative pressure began to drop was recorded. Specifically, if the dressing becomes clogged, the negative pressure source cannot continue to provide negative pressure to the wound dressing 10 and the negative pressure at the wound dressing 10 will begin to drop. The specific test results are shown in the following table:

wound dressing	Time to onset of occlusion
		The first embodiment of the present application	91h
Example two of the present application	92h
		Example three of the present application	70h
Example four of the present application	91h
		Related art embodiment 1	89h
Related art example two	54h
		Related art example three	59h

As can be seen from the above table, thewound dressings 10 in the first to fourth examples of the present application all started to occlude for about 90 hours, which was extended by about 30 hours compared to 54 hours in the second related art example and 59 hours in the third related art example.

On the other hand, the present application also tested the conformability of the first to fourth embodiments of the present application and the first to third embodiments of the related art.

Specifically, as shown in fig. 9, fig. 9 is a schematic diagram of the application of the test for the conformability, wherein a first end of a long and narrow dressing with a length of 153mm and a width of 53mm is fixed on the upper surface P1 of the platform (the length of about 40mm is fixed on the horizontal upper surface P1), a second end is suspended (the length of about 113mm is suspended in the air), a distance L is measured between the second end and the side surface P2 of the platform (the distance L is about small, which indicates that the conformability of the wound dressing is better), and the side surface P2 is vertically connected with the upper surface P1. The specific test results are shown in the following table:

wound dressing	Distance L
		The first embodiment of the present application	84mm
Example two of the present application	85mm
		Third embodiment of the present application	94mm
Example four of the present application	89mm
		Related art embodiment 1	105mm
Example II of the related art	91mm
		Related art example three	92mm

In yet another aspect, the present application provides a negative pressure wound therapy device.

Referring to fig. 10, fig. 10 is a schematic structural diagram of an embodiment of the negative pressure wound therapy device according to the present application. The negative pressure wound therapy device includes a wound dressing 10, aconnection assembly 20, and anegative pressure source 30. The wound dressing 10 may be any of the structures previously described herein. Theconnection assembly 20 is used to enable fluid communication between the backing layer 1 opening 1a and thenegative pressure source 30. Specifically, theconnection assembly 20 includes aconnector 21 adhered to the upper surface of the backing layer 1 and a conduit 22 connected to theconnector 21. The conduit 22 is connected at one end to theconnector 21 and at the other end to anegative pressure source 30. Anegative pressure source 30 provides negative pressure to the wound dressing 10 via theconnection assembly 20.

The terms "first", "second" and "third" in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any indication of the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of the feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless explicitly specifically limited otherwise. All directional indications (such as up, down, left, right, front, and rear … …) in the embodiments of the present application are only used to explain the relative positional relationship between the components, the movement, and the like in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indication is changed accordingly. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

The above description is only a part of the embodiments of the present application, and not intended to limit the scope of the present application, and all equivalent devices or equivalent processes performed by the content of the present application and the attached drawings, or directly or indirectly applied to other related technical fields, are also included in the scope of the present application.

Claims (12)

1. A wound dressing for negative pressure therapy, the wound dressing comprising:

a backing layer having an opening disposed therein for fluid communication with a source of negative pressure;

the absorption bag is arranged on one side of the backing layer and comprises a first structural layer and a second structural layer, the peripheries of the second structural layer and the first structural layer are jointed to form an accommodating space, and the first structural layer is closer to the backing layer than the second structural layer;

the absorption layer is arranged in the accommodating space;

at least one pressure distribution layer disposed on the same side of the backing layer as the absorbent pouch, the pressure distribution layer being located on a side of the absorbent layer proximal to the backing layer and/or on a side of the absorbent layer facing away from the backing layer;

wherein the softness of the first structural layer is greater than the softness of the pressure distribution layer, and the softness of the second structural layer is greater than the softness of the pressure distribution layer.

2. The wound dressing of claim 1, wherein the pressure distribution layer and the second structural layer are each of a three-dimensional structure, the pressure distribution layer having one layer disposed between the backing layer and the absorbent layer.

3. The wound dressing of claim 2, wherein the pressure distribution layer is disposed between the first structural layer and the absorbent layer.

4. The wound dressing of claim 2, wherein the pressure distribution layer is disposed between the backing layer and the first structural layer.

5. A wound dressing according to claim 3 or 4, wherein the orthographic projection of the pressure distribution layer on the plane of the absorbent layer lies wholly on the absorbent layer.

6. The wound dressing of claim 2, wherein the first structural layer is made of a material selected from the group consisting of polypropylene nonwoven fabric, nylon fabric, and polyester fabric.

7. The wound dressing of claim 1, wherein the first structural layer and the pressure distribution layer are each of a three-dimensional structure, the pressure distribution layer having one layer and being disposed on a side of the absorbent layer facing away from the backing layer.

8. The wound dressing of claim 1, wherein the first structural layer and the second structural layer are ultrasonically welded around.

9. The wound dressing of claim 1, further comprising a wound contact layer, the absorbent pouch and the pressure distribution layer being disposed between the backing layer and the wound contact layer, the wound contact layer comprising a silicone gel.

10. The wound dressing of claim 9, wherein at least a portion of the surface of the backing layer on the side adjacent to the wound contact layer is provided with adhesive in spots, and the perimeter of the backing layer is bonded to the perimeter of the wound contact layer by the adhesive.

11. The wound dressing of claim 1, further comprising a water-blocking breathable membrane attached to the backing layer and covering at least the opening.

12. A negative pressure wound therapy apparatus, comprising a negative pressure source for providing negative pressure to a wound dressing according to any one of claims 1 to 11 and the wound dressing.

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