Bandages for negative pressure wound therapy (NPWT) to accommodate the biological structure during breast augmentation surgery

Abstract

A bandage for negative pressure wound therapy (NPWT) to apply negative pressure to a wound is a membrane positioned above the wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an intermediate foam layer positioned between them, with an opening formed on the wound side that is in fluid communication with the wound chamber, and comprising a membrane including a linearly extended portion and a radially extended portion, and a negative pressure source that is fluidly connected to the opening in the membrane and applies negative pressure of air to the wound chamber.

Description

TECHNICAL FIELD

[0001] Reference to Co-Pending Prior Patent Application This application claims the benefit of co-pending prior U.S. Provisional Patent Application No. 63 / 539,975, filed September 22, 2023 by Guard Medical SAS and Machiel van der Leest et al., entitled "NEGATIVE PRESSURE WOUND THERAPY (NPWT) BANDAGE FOR ACCOMMODATING ANATOMY DURING MAMMOPLASTY, INCLUDING MASTOPEXY AND REDUCTION MAMMOPLASTY" (Attorney Docket No. GM-23 PROV).

[0002] The above-identified patent application is incorporated herein by reference.

[0003] The present invention relates generally to bandages, and more particularly to bandages for negative pressure wound therapy (NPWT).

BACKGROUND ART

[0004] Bandages are used for wound healing during treatment. More specifically, during treatment, the wound is generally covered with a bandage to protect the wound from contaminants and microorganisms. Most bandages also provide a closure function that helps hold the wound edges in close juxtaposition during treatment. Bandages also often include gauze or the like that receives exudate exiting from the wound during treatment.

[0005] Negative pressure wound therapy (NPWT) bandages apply negative pressure to the wound during treatment. This negative pressure helps to reduce the possibility of contaminants and microorganisms entering the wound during treatment, and helps to drain exudate from the wound during treatment, potentially promoting beneficial biological responses at the wound site. More specifically, an NPWT bandage typically comprises (i) an absorbent dressing configured to form a complete sealing chamber ("wound chamber") around the wound, (ii) a negative pressure source, and (iii) a conduit extending between the complete sealing wound chamber and the negative pressure source. As a result of this configuration, the application of the absorbent dressing to the wound can form a complete sealing chamber around the wound, and the negative pressure source can apply negative pressure to the complete sealing wound chamber, thereby removing any contaminants and microorganisms present at the wound site, draining exudate from the wound, and promoting beneficial biological responses at the wound site.

[0006] Most NPWT bandages are part of a large, complex NPWT system, which means that (i) the absorbent dressing is generally quite large (e.g., sized to cover a large open wound), (ii) the negative pressure source is generally quite large and is formed and positioned separately from the absorbent dressing (e.g., the negative pressure source usually consists of an electric suction pump or vacuum canister), and (iii) NPWT systems generally require considerable training to use. Also, these NPWT systems tend to be quite expensive.

[0007] To date, efforts have been made to provide smaller, simpler, and less expensive NPWT bandages by integrating the negative pressure source with the absorbent dressing. As a non-limiting example, efforts have been made to provide NPWT bandages in which a manually operated suction pump is incorporated into the absorbent dressing. Unfortunately, current NPWT bandages with integrated suction pumps tend to have various drawbacks, such as complex design, high cost, difficulty of use, bulkiness (high profile), trauma to the wound during use, low pump efficiency, lack of indication of the level of negative pressure generated, and / or lack of a way to limit the level of negative pressure generated. In the latter respect, it goes without saying that if the level of negative pressure generated is too high, the NPWT bandage can cause trauma to the patient, such as blister formation and capillary leakage.

[0008] Therefore, there is a need for a novel and improved NPWT bandage that is simple, inexpensive, easy to use, small in size (having a low profile), does not injure the wound during use, has improved pump efficiency, incorporates an automatic pressure indicator to show the level of negative pressure generated, and provides an automatic pressure limiter to limit the level of negative pressure generated. [Overview of the project]

[0009] The above and other objectives of the present invention are achieved by providing and using a novel and improved bandage for NPWT that is simple, inexpensive, easy to use, small in size (having a low profile), does not injure wounds during use, has improved pump efficiency, incorporates an automatic pressure indicator to show the level of negative pressure generated, and provides an automatic pressure limiter to limit the level of negative pressure generated.

[0010] In a preferred embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, The pump assembly is supported by the aforementioned membrane, A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through the opening formed in the membrane, A wound-side one-way valve is disposed in the wound-side passage, and is configured to allow fluid to flow from the wound chamber through the wound-side passage to the pump chamber, while preventing fluid from flowing from the pump chamber through the wound-side passage to the wound chamber. An atmospheric passage extending through the aforementioned wall structure and connecting the pump chamber and the atmosphere, An atmospheric-side one-way valve disposed in the atmospheric-side passage, configured to allow fluid to flow from the pump chamber through the atmospheric-side passage to the atmosphere, while preventing fluid from flowing from the atmosphere through the atmospheric-side passage to the pump chamber; A pump assembly comprising, Equipped with, A bandage for an NPWT is provided, which, when a compressive force is applied to the wall structure of the pump body, causes the fluid in the pump chamber to be pushed out of the pump chamber through the atmospheric passage, and then, when the compressive force applied to the wall structure of the pump body decreases, causes the fluid in the wound chamber to be drawn back into the pump chamber through the wound passage.

[0011] Preferably, the NPWT bandage is configured such that when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure falls below a predetermined threshold, the pump body of the pump assembly is in a substantially fully expanded state, and when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure exceeds the predetermined threshold, the pump body of the pump assembly is in a substantially fully contracted state.

[0012] It is even more preferable that the NPWT bandage is configured to effectively constitute a substantially "binary state" device by rapidly changing the state of the pump body between the substantially fully expanded state and the substantially fully contracted state, and between the substantially fully contracted state and the substantially fully expanded state, when the pressure difference crosses the predetermined threshold.

[0013] In another preferred embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, The pump assembly is supported by the aforementioned membrane, A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through the opening formed in the membrane, A wound-side one-way valve is disposed in the wound-side passage, and is configured to allow fluid to flow from the wound chamber through the wound-side passage to the pump chamber, while preventing fluid from flowing from the pump chamber through the wound-side passage to the wound chamber. An atmospheric passage extending through the aforementioned wall structure and connecting the pump chamber and the atmosphere, An atmospheric-side one-way valve disposed in the atmospheric-side passage, configured to allow fluid to flow from the pump chamber through the atmospheric-side passage to the atmosphere, while preventing fluid from flowing from the atmosphere through the atmospheric-side passage to the pump chamber; A pump assembly comprising, Equipped with, When a compressive force is applied to the wall structure of the pump body, the fluid in the pump chamber is pushed out of the pump chamber through the atmospheric passage, and then, when the compressive force applied to the wall structure of the pump body decreases, the fluid in the wound chamber is drawn back into the pump chamber through the wound passage. The negative pressure wound therapy (NPWT) bandage is placed above the wound to form a wound chamber between the membrane and the wound. After applying a compressive force to the wall structure of the pump body, the compressive force applied to the wall structure of the pump body is reduced to apply negative pressure to the wound. A method is provided that includes this.

[0014] In another preferred embodiment of the present invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, A pump comprising a wall chamber supported by the aforementioned membrane and arranged around a pump chamber, wherein at least a portion of the wall chamber is elastic, and further, the pump chamber communicates with a wound chamber through the opening formed in the membrane, and Equipped with, A bandage for NPWT is provided, which is not defined by any part of the pump chamber.

[0015] In another preferred form of the present invention, there is provided a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, a membrane disposed over the wound and configured to form a wound chamber between the membrane and the wound, the membrane comprising a wound side, an atmosphere side, and an aperture extending through the membrane from the wound side to the atmosphere side; a pump supported by the membrane and comprising a wall chamber disposed around a pump chamber, wherein at least a portion of the wall chamber is elastic, and further wherein the pump chamber is in communication with the wound chamber through the aperture formed in the membrane; comprising, there is provided an NPWT bandage, wherein the pump does not apply positive pressure to the wound.

[0016] In another preferred form of the present invention, there is provided a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, a membrane disposed over the wound and configured to form a wound chamber between the membrane and the wound, the membrane comprising a wound side, an atmosphere side, and an aperture extending through the membrane from the wound side to the atmosphere side; a pump supported by the membrane and comprising a wall chamber disposed around a pump chamber, wherein at least a portion of the wall chamber is elastic, and further wherein the pump chamber is in communication with the wound chamber through the aperture formed in the membrane; comprising, there is provided an NPWT bandage, wherein the pump is connected to the wound chamber such that a reduction in the volume of the pump chamber does not cause a change in the pressure in the wound chamber.

[0017] In another preferred form of the present invention, this bandage for negative pressure wound therapy (NPWT) is configured to also provide a negative pressure decay "alert condition" indicator.

[0018] In one form of the present invention, there is provided a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, a membrane disposed above a wound and configured to form a wound chamber between the membrane and the wound, the membrane comprising a wound side, an atmosphere side, and an opening extending through the membrane from the wound side to the atmosphere side; and a pump assembly supported by the membrane, a pump body comprising a wall structure disposed around a pump chamber, at least a portion of the wall structure being elastic, and the pump chamber being in communication with the wound chamber through the opening formed in the membrane; and an atmosphere-side passage extending through the wall structure and fluidly connecting the pump chamber to the atmosphere, comprising the pump assembly being configured such that when a compressive force is applied to the wall structure of the pump body, fluid in the pump chamber is pushed out of the pump chamber through the atmosphere-side passage, and then when the compressive force applied to the wall structure of the pump body is reduced, fluid in the wound chamber is drawn into the pump chamber through the opening formed in the membrane; and comprising when a pressure difference between the pressure of the fluid in the pump chamber and the atmospheric pressure is below a predetermined threshold, the pump body assumes a substantially fully expanded configuration, which indicates that the negative pressure in the wound chamber is below the predetermined threshold, and when the pressure difference between the pressure of the fluid in the pump chamber and the atmospheric pressure exceeds the predetermined threshold, the pump body assumes a substantially fully contracted configuration, which indicates that the negative pressure in the wound chamber exceeds the predetermined threshold, Further, a bandage for NPWT is provided, wherein the pump body is configured to provide a visual indicator that the negative pressure in the wound chamber is decreasing, but the decrease is not sufficient to drop below a predetermined threshold to cause the pump body to change to its substantially fully expanded configuration.

[0019] In another aspect of the present invention, there is provided a method for applying negative pressure to a wound, the method comprising providing a bandage for negative pressure wound therapy (NPWT), the bandage for NPWT comprising A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around a pump chamber, wherein at least a portion of the wall structure is elastic, and furthermore, the pump chamber communicates with a wound chamber through an opening formed in the membrane, An atmospheric side passage extends through the wall structure and fluidly connects the pump chamber to the atmosphere. Equipped with, When a compressive force is applied to the wall structure of the pump body, the fluid in the pump chamber is pushed out of the pump chamber through the atmospheric passage, and then, when the compressive force applied to the wall structure of the pump body decreases, the fluid in the wound chamber is drawn back into the pump chamber through the opening formed in the membrane. This demonstrates that when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure falls below a predetermined threshold, the pump body enters a substantially fully expanded configuration, thereby causing the negative pressure in the wound chamber to fall below a predetermined threshold. It also demonstrates that when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure exceeds a predetermined threshold, the pump body enters a substantially fully contracted configuration, thereby causing the negative pressure in the wound chamber to exceed a predetermined threshold. Furthermore, the pump assembly is configured to provide a visual indicator that the negative pressure in the wound chamber is decreasing, but not below a predetermined threshold, which would cause the pump to change to its substantially fully inflated configuration. To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, After applying a compressive force to the wall structure of the pump body, the compressive force applied to the wall structure of the pump body is reduced to apply negative pressure to the wound. A method is provided that includes this.

[0020] In another preferred embodiment of the present invention, the bandage for negative pressure wound therapy (NPWT) includes a canister for collecting exudate.

[0021] In one embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising, A canister configured to communicate fluidly with the wound chamber and pump assembly, and having an internal chamber for collecting exudate from the wound chamber. Equipped with, A bandage for NPWT is provided, in which the pump assembly is configured to generate negative air pressure within the wound chamber so that exudate from the wound chamber flows from the wound chamber into the internal chamber of the canister.

[0022] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising, A canister configured to communicate fluidly with the wound chamber and pump assembly, and having an internal chamber for collecting exudate from the wound chamber. Equipped with, The pump assembly is configured to generate negative air pressure within the wound chamber so that exudate from the wound chamber flows from the wound chamber into the internal chamber of the canister. The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, To create negative air pressure within the wound chamber so that exudate flows from the wound chamber into the internal chamber of the canister, A method is provided that includes this.

[0023] In another preferred embodiment of the present invention, the bandage for negative pressure wound therapy (NPWT) includes a Luer lock for suction attachment.

[0024] In one embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising, A suction source is connected to the pump assembly and configured to establish negative air pressure within the wound chamber. Equipped with, A bandage for NPWT is provided, wherein the pump body is configured to be substantially fully inflated when the negative air pressure in the wound chamber falls below a predetermined threshold, and substantially fully deflated when the negative air pressure in the wound chamber exceeds a predetermined threshold.

[0025] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening in the membrane, An atmospheric passage extending through the wall structure connects the pump chamber and the atmosphere. A pump assembly comprising, A suction source is connected to the pump assembly and configured to establish negative air pressure within the wound chamber. Equipped with, The system is designed so that when the negative air pressure inside the wound chamber falls below a predetermined threshold, the pump body enters a substantially fully inflated configuration, and when the negative air pressure inside the wound chamber exceeds a predetermined threshold, the pump body enters a substantially fully deflated configuration. The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, The suction source is connected to the pump assembly to generate negative air pressure within the wound chamber. A method is provided that includes this.

[0026] In another embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an opening extending through the membrane from the wound side to the air side, It is a pump assembly supported by a membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising, To establish negative air pressure within the wound chamber, a connector is used to connect the suction source to the pump assembly. Equipped with, A bandage for NPWT is provided, wherein the pump body is configured to be substantially fully inflated when the negative air pressure in the wound chamber falls below a predetermined threshold, and substantially fully deflated when the negative air pressure in the wound chamber exceeds a predetermined threshold.

[0027] In another preferred embodiment of the present invention, the negative pressure wound therapy (NPWT) bandage is provided with a pump assembly that is offset laterally from the wound while maintaining fluid communication with the wound.

[0028] In one embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane comprising a first portion positioned above the wound and configured to form a wound chamber between itself and the wound, and a second portion configured to extend laterally from the wound, the membrane comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber, and the membrane The pump assembly is supported by the second part of the membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising Equipped with, A bandage for NPWT is provided, in which the pump assembly is configured to generate negative air pressure within the wound chamber.

[0029] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane comprising a first portion positioned above the wound and configured to form a wound chamber between itself and the wound, and a second portion configured to extend laterally from the wound, the membrane comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber, and the membrane The pump assembly is supported by the second part of the membrane. A pump body including a wall structure arranged around the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening formed in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. A pump assembly comprising Equipped with, The pump assembly is configured to generate negative air pressure within the wound chamber, and is prepared accordingly. The first portion of the NPWT bandage is positioned above the wound to form a wound chamber between the membrane and the wound, and the second portion of the membrane, which is offset laterally from the wound, is positioned on the biological structure. Creating negative air pressure inside the wound chamber and A method is provided that includes this.

[0030] In another preferred embodiment of the present invention, a negative pressure wound therapy bandage for covering a wound is provided, comprising a transparent top layer that traps a foam layer against the wound, the foam layer having a series of windows that (i) allow direct visualization of the wound and (ii) provide a criterion along the length of the bandage to indicate whether the bandage needs to be replaced. The foam layer also comprises periphery serrations to allow the bandage to conform to curved wounds. This novel negative pressure wound therapy bandage may be used with an on-board pump or a pump located away from the bandage (or another suction source, e.g., wall suction). This novel bandage may also be used without applying negative pressure to the wound.

[0031] In one embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber. The membrane comprises a transparent layer and an absorbent layer, with the absorbent layer positioned on the wound side of the membrane. The absorption layer comprises a plurality of windows extending through the absorption layer, Furthermore, multiple windows in the transparent layer and the absorbent layer of the membrane enable visualization of the wound through the membrane, It is a pump assembly supported by a membrane. A pump body including a wall structure defining the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. Equipped with, A pump assembly configured to generate negative air pressure within the wound chamber and A bandage for NPWT is provided, equipped with the following features.

[0032] In another embodiment of the present invention, a bandage for covering a wound that discharges exudate, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber, The membrane comprises a transparent layer and an absorbent layer, with the absorbent layer positioned on the wound side of the membrane. The absorption layer comprises a plurality of windows extending through the absorption layer, Furthermore, the bandage is provided in which multiple windows in the transparent and absorbent layers of the membrane allow for visualization of the wound through the membrane.

[0033] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane positioned above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber. The membrane comprises a transparent layer and an absorbent layer, with the absorbent layer positioned on the wound side of the membrane. The absorption layer comprises a plurality of windows extending through the absorption layer, Furthermore, multiple windows in the transparent layer and the absorbent layer of the membrane enable visualization of the wound through the membrane, It is a pump assembly supported by a membrane. A pump body including a wall structure defining the pump chamber, wherein at least a portion of the wall structure is elastic, A wound-side passage extends through the wall structure and communicates with the wound chamber through an opening formed in the membrane, An atmospheric side passage extends through the wall structure and connects the pump chamber to the atmosphere. Equipped with, A pump assembly configured to generate negative air pressure within the wound chamber and To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, Creating negative air pressure inside the wound chamber, Visualizing the absorption layer of the membrane to determine whether removal of the NPWT bandage from the wound and replacement with a new NPWT bandage are necessary. A method is provided that includes this.

[0034] In another embodiment of the present invention, a method for covering a wound that releases exudate, This involves preparing bandages, and bandages are, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and an opening extending from the wound side to the atmospheric side, the opening being in fluid communication with the wound chamber, The membrane comprises a transparent layer and an absorbent layer, with the absorbent layer positioned on the wound side of the membrane. The absorption layer comprises a plurality of windows extending through the absorption layer, Furthermore, multiple windows in the transparent layer and the absorbent layer of the membrane are provided to enable visualization of the wound through the membrane. The bandage is placed above the wound to form a wound chamber between the membrane and the wound, Visualizing the absorption layer of the membrane to determine whether the bandage needs to be removed from the wound and replaced with a new one, A method is provided that includes this.

[0035] In another embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an intermediate foam layer disposed between them, with an opening formed on the wound side that is in fluid communication with the wound chamber, and comprising a linearly extended portion and a radially extended portion, A negative pressure source is connected to the opening in the membrane to apply negative air pressure to the wound chamber. A bandage for NPWT is provided, equipped with the following features.

[0036] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an intermediate foam layer disposed between the two, with an opening formed on the wound side that is in fluid communication with the wound chamber, and including a linearly extended portion and a radially extended portion, A negative pressure source is connected to the opening in the membrane to apply negative air pressure to the wound chamber. To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, Creating negative air pressure inside the wound chamber and A method is provided that includes this.

[0037] In another embodiment of the present invention, a bandage for negative pressure wound therapy (NPWT) for applying negative pressure to a wound, A first membrane disposed above the wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and a first intermediate foam layer disposed between them, wherein an opening that fluidly communicates with the wound chamber extends through the first membrane, and the first membrane comprises a linearly extended portion and a radially extended portion, A second membrane configured to be positioned above the first membrane, comprising a wound side, an air side, and a second intermediate foam layer positioned between the two, wherein an opening for fluid communication with the wound chamber is formed on the wound side of the second membrane, A pump assembly attached to the atmospheric side of the second membrane, which is fluid-connected to the opening in the second membrane and the opening in the first membrane, and applies negative pressure to the wound chamber. A bandage for NPWT is provided, equipped with the following features.

[0038] In another embodiment of the present invention, a method for applying negative pressure to a wound, This involves preparing bandages for negative pressure wound therapy (NPWT), and NPWT bandages are, A first membrane disposed above the wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and a first intermediate foam layer disposed between them, wherein an opening that fluidly communicates with the wound chamber extends through the first membrane, and the first membrane comprises a linearly extended portion and a radially extended portion, A second membrane is configured to be positioned above the first membrane, and comprises a wound side, an air side, and a second intermediate foam layer positioned between the two, with an opening formed on the wound side that is in fluid communication with the wound chamber. A pump assembly attached to the atmospheric side of the second membrane, which is fluid-connected to the opening in the second membrane and the opening in the first membrane, and applies negative pressure to the wound chamber. To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound, Creating negative air pressure inside the wound chamber and A method is provided that includes this.

[0039] The above and other objects and features of the present invention are more fully disclosed or expressed by the following detailed description relating to preferred embodiments of the invention, which should be considered in conjunction with the accompanying drawings, the same numbers representing the same parts. [Brief explanation of the drawing]

[0040] [Figure 1] This is a schematic diagram showing a novel and improved NPWT bandage formed according to the present invention. [Figure 2] This is an exploded schematic diagram showing a novel and improved NPWT bandage formed according to the present invention. [Figure 3] This is an exploded schematic diagram showing a novel and improved NPWT bandage formed according to the present invention. [Figure 4] This is a schematic diagram showing a novel and improved NPWT bandage formed according to the present invention. [Figure 4A] This schematic diagram shows the maximum negative pressure that can be established for two different sizes of wound chambers (i.e., a 7.5 mL wound chamber and a 15 mL wound chamber) using (i) a deformable pump body with two one-way valves (one one-way valve on each side of the deformable pump body) and (ii) a deformable pump body with a single one-way valve (note that in the comparison shown in Figure 4A, the volume of the pump chamber of the deformable pump body with one one-way valve is the same as the volume of the pump chamber of the deformable pump body with two one-way valves). [Figure 5] Figures 1 to 4 are schematic diagrams showing the pump body of the NPWT bandage in a substantially fully inflated configuration. [Figure 6] Figures 1 to 4 are schematic diagrams showing the pump body of the NPWT bandage in a substantially fully retracted configuration. [Figure 7] Figures 1 to 4 are schematic diagrams illustrating how the pump body of the NPWT bandage pump assembly rapidly changes state between a substantially fully expanded configuration and a substantially fully contracted configuration. [Figure 8]This is a schematic diagram illustrating how the pump body of a conventional NPWT bandage pump assembly gradually changes its state between a substantially fully expanded configuration and a substantially fully contracted configuration. [Figure 9] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage. [Figure 10] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage. [Figure 11] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage (Note that in Figure 11, the detachable cap 100 (see below) has been removed from the drawing for clarity). [Figure 12] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage. [Figure 13] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage. [Figure 14] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage (Note that in Figure 14, the detachable cap 100 (see below) has been removed from the drawing for clarity). [Figure 15] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage (Note that in Figure 15, the detachable cap 100 (see below) has been removed from the drawing for clarity). [Figure 16] Figures 1 to 4 are schematic diagrams illustrating exemplary use of the new, improved NPWT bandage (Note that in Figure 16, the detachable cap 100 (see below) has been removed from the drawing for clarity). [Figure 17] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 18] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 19]This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 20] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 20A] This is a schematic diagram showing how the configuration of the pump body changes during use (Note that in Figure 20A, for clarity of illustration, only the outer boundary of the pump's side wall 65 is shown, and the pump's flange 75 and neck 77 are omitted). [Figure 21] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 22] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 23] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 24] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 25] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 26] A schematic diagram shows another novel and improved bandage for an NPWT formed according to the present invention (the pump body is also configured to provide a negative pressure decay "warning state" indicator). [Figure 27] A schematic diagram shows another novel and improved bandage for an NPWT formed according to the present invention (the pump body is also configured to provide a negative pressure decay "warning state" indicator). [Figure 28] This schematic diagram shows how the configuration of the pump body, which is equipped with a negative pressure decay "warning state" indicator, changes during use (Note that in Figure 28, only the outer boundary of the pump's side wall is shown for clarity). [Figure 29] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 30] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 31] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 32] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 33] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 34] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention. [Figure 35] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 36] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 37] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 38] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 39]This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 40] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 41] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 42] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 43] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 44] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 45]This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 46] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 46A] This is a schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the wound chamber is provided with a lateral extension, and the pump assembly is in fluid communication with the lateral extension, thereby being offset laterally from the wound while maintaining fluid communication with the wound. [Figure 47] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the bandage comprises a transparent top layer that traps a foam layer against the wound, the foam layer is provided with a series of windows that (i) allow direct visualization of the wound and (ii) provide a criterion along the length of the bandage to indicate whether the bandage needs to be replaced, and the foam layer also comprises periphery serrations that allow the bandage to conform to curved wounds, and in this embodiment of the present invention, the NPWT bandage comprises a mounted pump offset laterally from the wound. [Figure 48]A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the bandage comprises a transparent top layer that traps a foam layer against the wound, the foam layer is provided with a series of windows that (i) allow direct visualization of the wound and (ii) provide a criterion along the length of the bandage to indicate whether the bandage needs to be replaced, and the foam layer also comprises periphery serrations that allow the bandage to conform to curved wounds, and in this embodiment of the present invention, the NPWT bandage comprises a mounted pump offset laterally from the wound. [Figure 49] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the bandage comprises a transparent top layer that traps a foam layer against the wound, the foam layer is provided with a series of windows that (i) allow direct visualization of the wound and (ii) provide a criterion along the length of the bandage to indicate whether the bandage needs to be replaced, and the foam layer also comprises periphery serrations that allow the bandage to conform to curved wounds, and in this embodiment of the present invention, the NPWT bandage comprises a mounted pump offset laterally from the wound. [Figure 50] Figures 47, 48, and 49 are schematic diagrams showing further details of the form layers. [Figure 51] Figure 47 is a schematic diagram showing the level of exudate in the foam layer of the bandage. [Figure 52] Figure 47 is a schematic diagram showing the level of exudate in the foam layer of the bandage. [Figure 53] This schematic diagram illustrates how a window in the foam layer allows healthcare professionals to position the bandage along the wound line. [Figure 54] This schematic diagram illustrates how a window in the foam layer allows healthcare professionals to position the bandage along the wound line. [Figure 55] This is a schematic diagram showing periphery serrations formed in the foam layer, which allow the bandage to curve to follow the path of a curved wound. [Figure 56]These schematic diagrams show how the NPWT bandages in Figures 47, 48, and 49 can be modified to position the mounted pump above a portion of the foam. [Figure 57] These schematic diagrams show how the NPWT bandages in Figures 47, 48, and 49 can be modified to position the mounted pump above a portion of the foam. [Figure 58] A schematic diagram illustrates how a general-purpose bandage may be provided, which includes a transparent top layer that traps a foam layer against a wound, as a result of a modification of the NPWT bandage in Figures 56 and 57, such as removing the mounted pump, wherein the foam layer is provided with a series of windows that (i) allow for direct visualization of the wound and (ii) provide criteria along the length of the bandage to indicate whether the bandage needs to be replaced, and further, the foam layer also includes periphery serrations to allow the bandage to be adapted to curved wounds. [Figure 59] A schematic diagram illustrates how a general-purpose bandage may be provided, which includes a transparent top layer that traps a foam layer against a wound, as a result of a modification of the NPWT bandage in Figures 56 and 57, such as removing the mounted pump, wherein the foam layer is provided with a series of windows that (i) allow for direct visualization of the wound and (ii) provide criteria along the length of the bandage to indicate whether the bandage needs to be replaced, and further, the foam layer also includes periphery serrations to allow the bandage to be adapted to curved wounds. [Figure 60] A schematic diagram illustrates how a general-purpose bandage may be provided, which includes a transparent top layer that traps a foam layer against a wound, as a result of a modification of the NPWT bandage in Figures 56 and 57, such as removing the mounted pump, wherein the foam layer is provided with a series of windows that (i) allow for direct visualization of the wound and (ii) provide criteria along the length of the bandage to indicate whether the bandage needs to be replaced, and further, the foam layer also includes periphery serrations to allow the bandage to be adapted to curved wounds. [Figure 61] This is a schematic diagram showing an example of a T-shaped incision used in breast augmentation surgery. [Figure 62]This is a schematic diagram showing another novel NPWT bandage formed according to the present invention. [Figure 63] Figure 62 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 64] Figure 62 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 65] This is a schematic diagram showing yet another novel NPWT bandage formed according to the present invention. [Figure 66] Figure 65 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 67] Figure 65 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 68] This is a schematic diagram showing yet another novel NPWT bandage formed according to the present invention. [Figure 69] Figure 68 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 70] Figure 68 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 71] This is a schematic diagram showing another novel NPWT bandage formed according to the present invention. [Figure 72] Figure 71 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 73] Figure 71 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 74] This is a schematic diagram showing yet another novel NPWT bandage formed according to the present invention. [Figure 75] Figure 74 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 76] Figure 74 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 77] This is a schematic diagram showing yet another novel NPWT bandage formed according to the present invention. [Figure 78]Figure 77 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 79] Figure 77 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 80] This is a schematic diagram showing another novel NPWT bandage formed according to the present invention. [Figure 81] Figure 80 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 82] Figure 80 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 83] This is a schematic diagram showing yet another novel NPWT bandage formed according to the present invention. [Figure 84] Figure 83 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 85] Figure 83 is a schematic diagram showing another embodiment of the novel NPWT bandage. [Figure 86] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 87] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 88] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 89]A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 90] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 91] A schematic diagram showing another novel and improved NPWT bandage formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage can be varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage. [Figure 92] This is a schematic diagram showing how a novel NPWT bandage formed according to the present invention can be used after mastoplasty. [Figure 93] This is a schematic diagram showing how a novel NPWT bandage formed according to the present invention can be used after mastoplasty. [Modes for carrying out the invention]

[0041] The present invention is achieved by providing and using a novel and improved bandage for NPWT that is simple, inexpensive, easy to use, small in size (having a low profile), does not injure wounds during use, has improved pump efficiency, incorporates an automatic pressure indicator to show the level of negative pressure generated, and provides an automatic pressure limiter to limit the level of negative pressure generated.

[0042] Overview of manually operated negative pressure wound therapy (NPWT) bandages For more details, first refer to Figures 1-4, which show a manually operated negative pressure wound therapy (NPWT) bandage 5 with improved pump efficiency, having an automatic pressure indicator to show the level of negative pressure to be generated and an automatic pressure limiter to limit the level of negative pressure to be generated.

[0043] The NPWT bandage 5 largely comprises a membrane (or sheet) 10 and a pump assembly 15.

[0044] As will be discussed below, the membrane 10 is configured to define the wound chamber by forming a complete sealing chamber around the wound.

[0045] Furthermore, as discussed below, the pump assembly 15 is configured to apply negative pressure to the fully sealed wound chamber, thereby removing any contaminants and microorganisms present at the wound site, as well as drawing out exudate and promoting beneficial biological responses at the wound site. Importantly, the pump assembly 15 is designed to improve pump efficiency and provide an automatic pressure indicator to show the level of negative pressure being generated and an automatic pressure limiter to limit the level of negative pressure being generated, as discussed below.

[0046] film More specifically, the membrane 10 includes a flat, planar sheet 20 formed from a flexible and substantially air-impermeable material (e.g., Tegaderm from 3M Company (also known as Minnesota Mining and Manufacturing Company)) so that it can conform to the contours of the body and form a substantially airtight chamber (i.e., wound chamber) around the wound. The membrane 10 is characterized by a wound side 25 and an air side 30. The membrane 10 is also characterized by an outer perimeter 35 and an inner opening 40.

[0047] Preferably, an adhesive 45 is provided on the wound side 25 of the membrane 10. Preferably, a release liner 50 is provided on the wound side 25 over the adhesive 45 so that the adhesive 45 remains covered until use.

[0048] Preferably, a removable stiffener 55 is provided on the air-facing side 30 of the membrane 10. The removable stiffener 55 helps to facilitate the handling of the NPWT bandage 5 (particularly the membrane 10) during removal of the NPWT bandage from the sterile packaging and placement of the NPWT bandage with respect to the wound. The removable stiffener 55 is intended to be removed from the membrane 10 after the NPWT bandage 5 has been fixed with respect to the wound site. The removable stiffener 55 may be provided as a single element, and more preferably as a pair of elements to facilitate removal of the NPWT bandage 5 from the membrane 10 after it has been fixed with respect to the wound site.

[0049] Pump Assembly The pump assembly 15 comprises a pump body 60 having a generally cylindrical shape and comprising side walls 65 and an inner chamber 70. The pump body 60 is formed from an elastic material (e.g., silicone) such that the side walls 65 are compressed inward by the application of an external force (e.g., crushing by the user's thumb and index finger), and then attempt to return to their original uncompressible state when the external force is removed. Preferably, a pump flange 75 is formed on one side of the pump body 60. As will be discussed in more detail below, the pump body 60 extends through the inner opening 40 of the membrane 10, and the upper surface of the pump flange 75 is fixed to the wound side 25 of the membrane 10 so that the pump assembly 15 is fixed and supported by the membrane 10. Preferably, the pump flange 75 is formed from a flexible material so that it can conform (at least to a limited extent) to the contour of the body. In one embodiment of the present invention, the pump body 60 and the pump flange 75 are integrally formed from the same material (e.g., silicone). In a preferred embodiment of the present invention, the side wall 65 of the pump body 60 and the pump flange 75 are joined by a neck 77 (Figure 5). In another preferred embodiment of the present invention, the neck 77 has a relatively small width relative to the entire diameter of the pump body 60, and a recess 78 extends inward between the membrane 10 and the pump body 60. Therefore, although the pump body 60 is attached to the pump flange 75, interference by the pump flange 75 is minimized, and radial compression / expansion is still free. A wound-side passage 80 is formed in the pump body 60 and communicates with the inner chamber 70. The wound-side passage 80 opens to the outside of the pump body 60 at a wound-side port 82. An atmospheric-side passage 85 is formed in the pump body 60 and also communicates with the inner chamber 70. The atmospheric-side passage 85 opens to the outside of the pump body 60 at an atmospheric-side port 87.

[0050] A wound-side one-way valve 90 is provided in the wound-side passage 80, and is configured to allow fluid to enter the inner chamber 70 through the wound-side passage 80, while preventing fluid from leaving the inner chamber 70 through the wound-side passage 80.

[0051] An atmospheric-side one-way valve 95 is provided in the atmospheric-side passage 85, and is configured so that fluid can flow out of the inner chamber 70 through the atmospheric-side passage 85, but cannot enter the inner chamber 70 through the atmospheric-side passage 85.

[0052] As a result of this configuration, if the pump body 60 of the pump assembly 15 is crushed manually (for example, by applying compressive force to the side walls 65 of the pump body 60 with the user's thumb and index finger), the fluid (e.g., air, liquid, etc.) in the inner chamber 70 is pushed out of the inner chamber 70 through the atmospheric side passage 85. Subsequently, if the pump body 60 of the pump assembly 15 is released (for example, by releasing the compressive force applied to the side walls 65 of the pump body 60 by the user's thumb and index finger), the fluid (e.g., air, liquid, etc.) on the underside of the wound side 25 of the membrane 10 (e.g., air, liquid, etc.) (e.g., air, liquid, etc. in the wound chamber) is drawn into the inner chamber 70 through the wound side passage 80 as the elastic side walls of the pump body return to their uncompressible state.

[0053] Furthermore, even if the pump body 60 of the pump assembly 15 is manually crushed, the one-way operation of the wound-side one-way valve 90 prevents the fluid (e.g., air, liquid, etc.) in the inner chamber 70 from leaving the inner chamber 70 through the wound-side passage 80. Subsequently, even if the pump body 60 of the pump assembly 15 is released, the one-way operation of the atmospheric-side one-way valve 95 prevents air from the atmosphere from being drawn into the inner chamber 70 through the atmospheric-side passage 85.

[0054] Therefore, naturally, repeated manual compression and release of the pump body 60 of the pump assembly 15 applies suction to the wound chamber located beneath the wound side 25 of the membrane 10, thereby generating negative pressure at the wound site.

[0055] Naturally, the present invention's method of providing a pump assembly in which two one-way valves are arranged in-line on both sides of a deformable pump body (i.e., the wound-side one-way valve 90 and the atmospheric-side one-way valve 95 are arranged on both sides of the deformable pump body 60) offers several important advantages that cannot be achieved with the prior art method of providing a deformable pump body that utilizes a single one-way valve.

[0056] More specifically, as discussed below, the present invention provides a pump assembly in which two one-way valves are arranged in-line on both sides of a deformable pump body (i.e., the wound-side one-way valve 90 and the atmospheric-side one-way valve 95 are arranged on both sides of the deformable pump body 60), enabling the establishment of substantially the same maximum negative pressure at the wound site regardless of the size of the wound chamber. This is not achievable with the prior art approach, which provides a deformable pump body utilizing a single one-way valve.

[0057] Furthermore, the present invention provides a pump assembly in which two one-way valves are arranged in-line on both sides of a deformable pump body (i.e., the wound-side one-way valve 90 and the atmospheric-side one-way valve 95 are arranged on both sides of the deformable pump body 60), which enables the realization of a constant selectable maximum negative pressure at the wound site, more so than can be achieved at the wound site by using a deformable pump body containing a single one-way valve (reflecting the prior art method).

[0058] More specifically, Figure 4A shows the maximum negative pressure that can be established for two different sizes of wound chambers (i.e., a 7.5 mL wound chamber and a 15 mL wound chamber) using (i) a deformable pump body with two one-way valves (one one-way valve on each side of the deformable pump body) and (ii) a deformable pump body with a single one-way valve (note that in the comparison shown in Figure 4A, the volume of the pump chamber of the deformable pump body with one one-way valve is the same as the volume of the pump chamber of the deformable pump body with two one-way valves).

[0059] Figure 4A contains several important aspects of the present invention.

[0060] Firstly, Figure 4A shows that by using a deformable pump body with two one-way valves (one one-way valve on each side of the deformable pump body) to aspirate the wound chamber, substantially the same maximum negative pressure (i.e., approximately -150.0 mmHg for a 7.5 mL wound chamber and approximately -150.0 mmHg for a 15 mL wound chamber) is established in the wound chamber regardless of the size of the wound chamber, whereas this is not achieved when using a deformable pump body with a single one-way valve (i.e., approximately -80.0 mmHg for a 7.5 mL wound chamber and approximately -50.0 mmHg for a 15 mL wound chamber). Thus, with the NPWT bandage of the present invention, substantially the same maximum negative pressure can be established at the wound site regardless of the size of the wound chamber, whereas this is not achieved with conventional NPWT bandages.

[0061] The unique features of this invention are clinically important because (i) it is generally desirable to establish a selectable maximum negative pressure (e.g., between approximately 60 mmHg and 180 mmHg) at the wound site, and (ii) it is generally difficult to determine the volume of the wound chamber in advance (e.g., due to changes in medical application, changes in the patient's biological structure, etc.). Therefore, with the NPWT bandage of the present invention, substantially the same maximum negative pressure can be established at the wound site regardless of the size of the wound chamber. This means that the NPWT bandage can be pre-processed (e.g., during manufacturing) to establish a selectable maximum negative pressure at the wound site, which is not possible with conventional NPWT bandages.

[0062] Secondly, Figure 4A shows that by using a deformable pump body with two one-way valves (one one-way valve on each side of the deformable pump body) to aspirate the wound chamber, a substantially higher maximum negative pressure can be established in the wound chamber than the negative pressure that can be established by using a deformable pump body with a single one-way valve (i.e., approximately -80.0 mmHg for a 7.5 mL wound chamber and approximately -50.0 mmHg for a 15 mL wound chamber) (i.e., approximately -150.0 mmHg for a 7.5 mL wound chamber and approximately -150.0 mmHg for a 15 mL wound chamber). Thus, with the NPWT bandage of the present invention, a substantially higher maximum negative pressure can be established at the wound site.

[0063] Furthermore, the pressure inside the inner chamber 70 of the pump body 60 is approximately equal to the pressure on the underside of the wound side 25 of the membrane 10 (that is, the pressure inside the inner chamber 70 of the pump body 60 is approximately equal to the pressure inside the wound chamber).

[0064] In another preferred embodiment of the present invention, the pump assembly 15 includes a removable cap 100. The removable cap 100 is configured to selectively close the atmospheric passage 85 with respect to the fluid flow when the removable cap 100 is inserted into the atmospheric passage 85 and closes the atmospheric port 87.

[0065] The pump assembly 15 is supported by the membrane 10 by being attached to it. More specifically, the pump assembly 15 is attached to the membrane 10 by (i) passing the pump body 60 of the pump assembly 15 through the inner opening 40 of the membrane 10, (ii) lifting the pump flange 75 relative to the wound side 25 of the membrane 10, and (iii) attaching the pump flange 75 to the wound side 25 of the membrane 10 (for example, by joining, bonding, etc.). The pump assembly 15 and the membrane 10 constitute a substantially airtight connection.

[0066] Importantly, the pump body 60 of the pump assembly 15 is carefully configured to (i) improve pump efficiency, (ii) provide an automatic pressure indicator to show the level of negative pressure being generated, and (iii) provide an automatic pressure limiter to limit the level of negative pressure being generated, as discussed below.

[0067] More specifically, the pump body 60 of the pump assembly 15 is configured to abruptly change between (i) a substantially fully expanded configuration (see Figure 5) in which the side walls 65 of the pump body 60 and the inner chamber 70 of the pump body 60 have substantially circular cross-sections when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure falls below a given threshold, and (ii) a substantially fully contracted configuration (see Figure 6) in which the side walls 65 of the pump body 60 curve inward when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure exceeds a given threshold.

[0068] Specifically, when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure falls below a given threshold, the pump body 60 of the pump assembly 15 enters a substantially fully expanded configuration (Figure 5), and when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure exceeds a given threshold, the pump body 60 of the pump assembly 15 enters a substantially fully contracted configuration (Figure 6).

[0069] Importantly, the pump body 60 of the pump assembly 15 is configured to abruptly change state between a substantially fully expanded configuration (Figure 5) and a substantially fully contracted configuration (Figure 6) when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure crosses the aforementioned given threshold. Referring to Figure 7, this is a graph showing the relationship between the diameter of the side wall 65 of the pump body 60 and the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure. Thus, the pump assembly 15 is specifically configured to behave essentially as a substantially "binary state" device that is either substantially fully expanded (Figure 5) or substantially fully contracted (Figure 6). In this regard, naturally, as used herein, the term “substantially “binary state” device” is intended to describe a device that tends to be either substantially fully expanded or substantially fully contracted, and as used herein, the term “substantially “binary state” behavior” is intended to describe a device that tends to be either substantially fully expanded or substantially fully contracted.

[0070] Furthermore, the pump body 60's essentially "binary state" behavior is a result of the pump body's formation by the side walls 65 having substantially circular cross-sections, giving the pump body "over-the-center" deformation characteristics. That is, the side walls of the pump body 60 have a "failure" mode in which it rapidly transitions from a substantially fully expanded configuration to a substantially fully contracted configuration, and a "restoration" mode in which it rapidly transitions from a substantially fully contracted configuration to a substantially fully expanded configuration (see Figure 7). Furthermore, by forming the pump assembly 15 such that the side walls 65 of the pump body 60 and the pump flange 75 are connected at the neck 77, which has a relatively small width relative to the total diameter of the pump body 60, and a recess 78 extends inward between the membrane 10 and the pump body 60 (Figure 5), the pump body 60 has substantially circular cross-sections around its entire circumference, interference by the pump flange 75 is minimized, and radial compression / expansion is free, thus allowing it to exhibit essentially "binary state" behavior.

[0071] In conventional methods for forming a pump body with a dome-shaped or square pump configuration, when the pressure difference between the fluid pressure in the inner chamber and atmospheric pressure changes, the pump body does not change its state abruptly. Instead, these conventional dome-shaped or square pump configurations allow the pump body to gradually change its state between an expanded configuration and a contracted configuration. Referring to Figure 8, this is a graph showing the relationship between the diameter of the side wall of a pump body with a dome-shaped or square configuration and the pressure difference between the fluid pressure in the inner chamber of the pump body and atmospheric pressure.

[0072] As a result of intentionally configuring the side walls 65 of the pump body 60 of the pump assembly 15 to exhibit the rapid state changes described above, the pump assembly 15 can improve pump efficiency and provide an automatic pressure indicator to show the level of negative pressure generated and an automatic pressure limiter to limit the level of negative pressure generated.

[0073] More specifically, the pump body 60 of the pump assembly 15 is configured to abruptly change state between a substantially fully expanded configuration and a substantially fully contracted configuration when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure crosses a given threshold, so that the pump assembly 15 effectively returns to its substantially fully expanded configuration as long as the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure falls below a given threshold. As a result, as long as the pressure difference between the fluid in the inner chamber 70 and atmospheric pressure falls below a given threshold, the pump assembly 15 returns to a substantially fully expanded configuration between compression (i.e., collapse) and compression, thus maintaining a sufficiently efficient state when negative pressure is applied to the wound chamber. This is in contrast to the performance of prior art devices, in which the pump body exhibits a stepwise change between expanded and contracted configurations as the pressure difference between the pump assembly and the fluid pressure in the inner chamber changes, so that as the pressure in the wound chamber decreases, the efficiency of the pump assembly also gradually decreases. This is because when negative pressure is generated in the wound chamber, the pump body has difficulty returning to its fully inflated state, and the amount of fluid that the pump assembly can draw in decreases with each collapse of the pump body. In other words, in conventional devices, when negative pressure is generated in the wound chamber, the efficiency of the pump assembly decreases.

[0074] In this regard, by configuring the pump body 60 to abruptly change state between a substantially fully expanded configuration and a substantially fully contracted configuration when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure crosses a given threshold, the pump assembly 15 can function as an automatic pressure indicator for indicating the level of negative pressure generated. That is, as long as the pump body 60 of the pump assembly 15 returns to its substantially fully expanded configuration between collapses, it will be readily apparent to the observer that the pressure in the inner chamber 70 (and consequently, the pressure in the wound chamber) will fall below a given level. This is in stark contrast to the performance of prior art devices. In the prior art, the pump body 60 undergoes a stepwise change between the expanded and contracted configurations when the pressure difference between the fluid pressure in the inner chamber of the pump assembly changes, but in this case, the pump assembly cannot function as an automatic pressure indicator for indicating the level of negative pressure generated.

[0075] In connection with this, the pump assembly 15 can function as an automatic pressure limiter to limit the level of negative pressure generated by configuring the pump body 60 to abruptly change state between a substantially fully expanded configuration and a substantially fully contracted configuration when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure crosses a given threshold. This is because as soon as the pump body 60 is in its substantially fully contracted configuration, the pump assembly 15 can no longer pump fluid from the wound chamber and essentially comes to a stop. This is in stark contrast to the performance of prior art devices, in which the pump body undergoes a stepwise change between expanded and contracted configurations when the pressure difference between the fluid pressure in the inner chamber changes, because at a given pressure difference, the pump assembly does not effectively come to a stop.

[0076] Naturally, the pressure difference required for the pump body 60 to transition between its substantially fully expanded configuration and substantially fully contracted configuration (i.e., the aforementioned “given threshold”) may be “adjusted” to a certain level by changing one or more properties of the pump body 60 (for example, forming the side walls 65 of the pump body 60 from a material having a specific hardness, adjusting the thickness of the side walls 65 of the pump body 60, adjusting the diameter of the inner chamber 70 of the pump body 60, etc.).

[0077] Generally, it has been found that superior therapeutic results can be achieved when the pressure difference required for the pump body 60 to transition between its substantially fully inflated configuration and its substantially fully deflated configuration (i.e., the aforementioned "given threshold") is approximately 60 mmHg to approximately 180 mmHg. In other words, it has been found that superior therapeutic results can be achieved when the pump body 60 transitions between its substantially fully inflated configuration (Figure 5) and substantially fully deflated configuration (Figure 6) at a negative pressure of approximately 60 mmHg to approximately 180 mmHg. When the pump body 60 transitions between its two states at a lower pressure (i.e., when the pump body 60 transitions at a negative pressure lower than approximately 60 mmHg), it is thought that the wound site does not receive sufficient suction for effective removal of contaminants and microorganisms from the wound site, effective removal of exudate from the wound site, and / or promotion of beneficial biological responses at the wound site. Furthermore, if the pump body 60 transitions between the two states at a higher pressure (i.e., if the pump body 60 transitions at a negative pressure higher than approximately 180 mmHg), the suction produced at the wound site may cause tissue trauma (e.g., blister formation, capillary leakage, etc.).

[0078] In a preferred embodiment of the present invention, the pump body 60 of the pump assembly 15 is configured to transition abruptly between a substantially fully expanded configuration and a substantially fully contracted configuration when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure exceeds 80 mmHg. Thus, in this embodiment of the present invention, as long as the negative pressure in the wound chamber (assuming atmospheric pressure is 760 mmHg) is less than 680 mmHg, the pump assembly 15 returns to its substantially fully expanded configuration during the collapse of the pump body, maintaining its pumping efficiency when applying suction to the wound chamber. Then, as soon as the negative pressure in the wound chamber (assuming atmospheric pressure is 760 mmHg) exceeds 680 mmHg, the pump assembly 15 immediately returns to its substantially fully contracted configuration, acting as an automatic pressure indicator that the level of negative pressure generated at the wound site has exceeded 80 mmHg, and the pump assembly 15 automatically stops to prevent the level of negative pressure generated at the wound site from exceeding 80 mmHg.

[0079] Furthermore, given that the pump body 60 of the pump assembly 15 has a substantially cylindrical structure, the NPWT bandage 5 has a low profile.

[0080] Furthermore, because the pump body 60 of the pump assembly 15 is configured to be crushed between the user's thumb and index finger, the compressive force applied to the pump body 60 is applied parallel to the surface of the skin, so no trauma is inflicted on the wound during use (i.e., when the pump assembly 15 is operating). This is in stark contrast to conventional NPWT bandages, which employ a dome-shaped configuration and therefore require the application of compressive force toward the wound.

[0081] Exemplary use In a preferred embodiment of the present invention, the following use of the NPWT bandage 5 is intended, with reference to Figures 9 to 16.

[0082] First, remove the NPWT bandage 5 from its box. In one embodiment of the present invention, each NPWT bandage 5 is contained in a separate sterile package, and multiple sterile packages are contained in a box (see Figure 9).

[0083] Next, remove NPWT bandage 5 from its sterile package (Figure 10) and prepare it for use (Figure 11).

[0084] To apply the NPWT bandage 5 to the wound site, the release liner 50 is removed from the wound side 25 of the membrane 10 (see Figure 12). Then, the wound side 25 of the membrane 10 is positioned against the wound, and the NPWT bandage 5 is positioned against the patient's skin so that the adhesive 45 fixes the NPWT bandage 5 to the patient's skin, thereby forming a substantially airtight seal with the patient's skin around the wound chamber (see Figure 13).

[0085] When the NPWT bandage 5 is applied to the patient's skin, the wound-side port 82 of the wound-side passage 80 of the pump assembly 15 opens into the wound chamber.

[0086] Furthermore, prior to the placement of the NPWT bandage 5 on the patient's skin, a gauze layer (or other absorbent wound dressing) 102 may be placed on the wound site, thereby interposing the gauze layer (or other absorbent wound dressing) between the wound and the wound-side passage 80 of the pump assembly 15. As a result, exudate from the wound will be absorbed by the gauze (or other absorbent wound dressing). In addition, the gauze layer (or other absorbent wound dressing) 102 may be attached (i.e., fixed) to the wound side of the membrane 10, for example during manufacturing, if necessary, so that the gauze layer (or other absorbent wound dressing) 102 is delivered to the wound site by the NPWT bandage 5 and applied to the wound simultaneously with the NPWT bandage 5.

[0087] Next, with the NPWT bandage 5 fixed to the patient's skin, the removable stiffener 55 is removed from the air-facing side 30 of the membrane 10 (see Figure 14).

[0088] At this point, negative pressure can be applied to the wound chamber by using the NPWT bandage 5. This is done by crushing the side wall 65 of the pump body 60 between the user's thumb and index finger, compressing the pump body 60 to its substantially fully contracted configuration, which expels fluid (e.g., air, liquid, etc.) from the inner chamber 70 of the pump body 60 through the atmospheric passage 85 and the atmospheric one-way valve 95 (see Figure 15). Note that because of the presence of the wound-side one-way valve 90, the fluid in the inner chamber 70 of the pump body 60 does not escape from the inner chamber 70 through the wound-side passage 80. Subsequently, when the side wall 65 of the pump body 60 is released, the elastic pump body 60 can return to its substantially fully expanded configuration, generating negative pressure in the inner chamber 70 and the wound-side passage 80, drawing the fluid on the underside of the wound side 25 of the membrane 10 (e.g., fluid in the wound chamber) into the inner chamber 70 through the wound-side passage 80 and the wound-side one-way valve 90. Furthermore, because of the presence of the atmospheric side one-way valve 95, atmospheric air does not enter the inner chamber 70 through the atmospheric side passage 85.

[0089] This process of compressing and releasing the side walls 65 of the pump body 60 is repeated until the pump body 60 of the pump assembly 15 maintains its substantially fully contracted configuration (i.e., until the side walls 65 of the pump body 60 curve inward), even if the side walls 65 of the pump body 60 are not manually compressed (see Figure 16). When the pump body 60 of the pump assembly 15 maintains its substantially fully contracted configuration, even if the side walls 65 of the pump body 60 are not manually compressed, the observer will understand that the pressure difference between the fluid pressure in the inner chamber 70 (and wound chamber) and atmospheric pressure has exceeded the desired threshold, and the desired level of negative pressure has been achieved at the wound site. Note that when the pump body 60 of the pump assembly 15 maintains its substantially fully contracted configuration, even if the side walls 65 of the pump body 60 are not manually compressed, the pump assembly 15 is effectively stopped, because it is impossible to continue using the pump assembly with the side walls 65 in their substantially fully contracted configuration.

[0090] At this point, the atmospheric port 87 of the atmospheric passage 85 can be sealed by using the detachable cap 100.

[0091] The NPWT bandage 5 remains in place on the wound for an appropriate period (e.g., several days) to protect the wound from contaminants and microorganisms during treatment, to drain exudate from the wound, and to promote a beneficial biological response at the wound site. If the negative pressure generated in the wound chamber falls below a given threshold due to leakage (which will be apparent to the observer due to the fact that the side wall 65 of the pump body 60 will return to its substantially fully inflated configuration), the desired negative pressure may be re-established in the wound chamber (i.e., by repeatedly compressing and releasing the side wall 65 of the pump body 60) by using the pump assembly 15 as described above, after opening the atmospheric port 87 of the atmospheric passage 85 (i.e., removing the detachable cap 100).

[0092] If necessary, the NPWT bandage 5 may be removed from the patient's skin by simply peeling the membrane 10 off the patient's skin.

[0093] Pump body including notches that reinforce the effective "binary state" behavior As described above, it is preferable that the pump body 60 of the pump assembly 15 is configured to rapidly change between (i) a substantially fully expanded configuration in which the side walls 65 of the pump body 60 and the inner chamber 70 of the pump body 60 have substantially circular cross-sections when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure falls below a given threshold (see Figure 5), and (ii) a substantially fully contracted configuration in which the side walls 65 of the pump body 60 curve inward when the pressure difference between the fluid pressure in the inner chamber 70 and atmospheric pressure exceeds a given threshold (see Figure 6).

[0094] Furthermore, as described above, the substantially "binary state" behavior of the pump body 60 is achieved by forming a pump body having a substantially circular cross-section, which gives the pump body a "dead point over" deformation characteristic. That is, the side walls of the pump body 60 have a "decline" mode in which they rapidly transition from a substantially fully expanded configuration to a substantially fully contracted configuration, and a "recovery" mode in which they rapidly transition from a substantially fully contracted configuration to a substantially fully expanded configuration (see Figure 7). As described above, the pump assembly 15 is formed such that the side walls 65 of the pump body 60 and the pump flange 75 are connected at the neck 77 which has a relatively small width relative to the total diameter of the pump body 60, and a recess 78 extends inward between the membrane 10 and the pump body 60 (Figure 5). As a result, the pump body 60 has a substantially circular cross-section substantially around its entire circumference, interference by the pump flange 75 is minimized, and radial compression / expansion is free, so the pump body 60 can exhibit substantially "binary state" behavior.

[0095] If necessary, the pump body 60 can be deformed to reinforce the pump body's essentially "binary state" behavior.

[0096] As a non-limiting example, as shown below with reference to Figures 17 to 20, the pump body 60's substantial "binary state" behavior can be further reinforced by forming notches 105 in the pump body 60 (for example, at the "9 o'clock," "12 o'clock," and "3 o'clock" positions) to further induce the pump body 60 to be in either its substantial fully expanded or substantial fully contracted configuration. The more the pump body 60 exhibits true "binary state" behavior, the higher the pump efficiency and the more effectively the pump assembly 15 functions as an automatic pressure indicator and automatic pressure limiter.

[0097] Therefore, referring to Figure 20A below, the pump body 60 is generally, The virtually complete expansion configuration before pump operation, The contraction and expansion configuration during pump operation, The "vertical" effective contraction configuration after achieving a given level of negative pressure through pump operation, A substantially complete expansion configuration after the decay of negative pressure below a given level, It will be a tightening.

[0098] Furthermore, after transitioning to a virtually fully expanded configuration, the desired negative pressure can be re-established by a new pump operation.

[0099] NPWT bandages that incorporate gauze (or other absorbent wound dressing) and utilize an improved pump assembly. Next, referring to Figures 21 to 25, these show another negative pressure wound therapy (NPWT) bandage 5 formed according to the present invention. The NPWT bandage 5 shown in Figures 21 to 25 is substantially the same as the NPWT bandage 5 shown in Figures 1 to 16 and Figures 17 to 20, except that (i) in the configurations shown in Figures 21 to 25, the membrane 10 includes multiple layers containing gauze (or other absorbable wound dressing), and (ii) in the configurations shown in Figures 21 to 25, the pump assembly 15 has a modified configuration and is fixed to the membrane 10 in a different manner.

[0100] More specifically, in this embodiment of the present invention, the membrane 10 includes a lower skin-contact polyurethane layer 110 having a central opening 115, an intermediate foam (or gauze or other absorbent wound dressing) layer 120 disposed above the central opening 115 of the lower skin-contact polyurethane layer 110, and an upper polyurethane layer 125 disposed above the intermediate foam layer 120 and the lower skin-contact polyurethane layer 110. In a preferred embodiment of the present invention, the upper polyurethane layer 125 is formed from a substantially air-impermeable material. Also in a preferred embodiment of the present invention, the upper polyurethane layer 125 and the lower skin-contact polyurethane layer 110 have the same outer circumference, so that the upper polyurethane layer 125 does not come into contact with the patient's skin. The outer circumferences of the upper polyurethane layer 125 and the lower skin-contact polyurethane layer 110 are fixed to each other, trapping the intermediate foam layer 120 between them. The intermediate foam layer 120 has an outer circumference that is (i) larger than the perimeter of the central opening 115 of the lower skin-contact polyurethane layer 110, and (ii) smaller than the outer circumference of the outer circumference of the lower skin-contact polyurethane layer 110 and the upper polyurethane layer 125. Thus, when the central opening 115 of the lower skin-contact polyurethane layer 110 of the NPWT bandage 5 is positioned above the wound, fluid from the wound can pass through the central opening 115 of the lower skin-contact polyurethane layer 110 and reach the intermediate foam layer 120. Naturally, adhesive 45 is placed on the wound side of the lower skin-contact polyurethane layer 110 so that the NPWT bandage 5 can establish a substantially airtight seal around the wound (i.e., so as to form the aforementioned wound chamber). An opening 130 is formed in the upper polyurethane layer 125, which overlaps with the central opening 115 of the lower skin-contact polyurethane layer 110, allowing the wound-side passage 80 of the pump assembly 15 to access fluid (e.g., air, liquid, etc.) in the wound chamber (i.e., through the opening 130 in the upper polyurethane layer 125, the opening in the intermediate foam layer 120, and the central opening 115 in the lower skin-contact polyurethane layer 110) and perform suction during the pumping operation of the pump assembly 15.

[0101] The pump assembly 15 used in the NPWT bandage 5 shown in Figures 21-25 is substantially similar to the pump assembly 15 described above, except that it comprises a pair of bases 135A and 135B for attaching the pump assembly 15 to the membrane 10. More specifically, base 135A includes one end of the pump body 60 and is attached (for example by adhesive 137) to the upper surface of the membrane 10 (i.e., the upper surface of the upper polyurethane layer 125), thereby aligning the wound-side passage 80 and the wound-side one-way valve 90 with the opening 130 of the upper polyurethane layer 125 (and thus establishing fluid communication with the wound chamber). Base 135B includes the other end of the pump body 60 and is attached (for example by adhesive 138) to the upper surface of the membrane 10 (i.e., the upper surface of the upper polyurethane layer 125). The intervening portion 140 of the pump body 60 is suspended between the bases 135A and 135B and raised above the upper polyurethane layer 125 of the membrane 10, thus forming a space 145 between the intervening portion 140 of the pump body 60 and the upper polyurethane layer 135 of the membrane 10. Although the intervening portion 140 of the pump body 60 is not directly attached to the membrane 10, the fact that it is suspended above the membrane 10 by the bases 135A and 135B allows the intervening portion 140 of the pump body 60 to be formed with a true circular cross-section, thereby reinforcing the substantial "binary state" behavior of the NPWT bandage. Naturally, the pump body 60 can further reinforce the substantial "binary state" behavior of the NPWT bandage by incorporating one or more of the aforementioned notches 105.

[0102] Bandage for NPWT including negative pressure attenuation "warning state" indicator It has also been found that the pump body 60 may be configured to provide a negative pressure decay "warning state" indicator as needed.

[0103] More specifically, by controlling the number, configuration, and arrangement of the notches 105, the pump body 60 may provide a “warning state” indicator that a negative pressure decay has occurred, even if the decay is not significant enough to cause a binary state transition of the pump body (i.e., a transition from a substantially contracted configuration to a substantially fully expanded configuration). As a non-limiting example, by providing a pump body having a number, configuration, and arrangement of notches 105 as appropriate, the pump body may provide a “warning state” indicator (indicating a negative pressure decay below a given level, but not significant enough to cause a binary state transition of the pump body from substantially fully contracted to substantially fully expanded) upon the transition of the pump body from a “vertical” substantially contracted configuration (which occurs after a given level of negative pressure has been achieved) to a “horizontal” substantially contracted configuration (which occurs after some decay of negative pressure has occurred, even if the decay is not significant enough to cause a binary state transition of the pump body back to a substantially fully expanded configuration).

[0104] Figures 26 and 27 show exemplary configurations in which a pump body having a suitable number, configuration, and arrangement of notches 105 can provide a “warning state” indicator (indicating that there is a negative pressure attenuation below a given level, but not enough attenuation to cause a binary state transition of the pump body to a binary state transition of the pump body to a fully expanded configuration) by transitioning the pump body from a “vertical” substantially contracted configuration (which occurs after a given level of negative pressure has been achieved) to a “horizontal” substantially contracted configuration (which occurs after some attenuation of negative pressure has occurred, but not enough attenuation to cause a binary state transition of the pump body to a fully expanded configuration).

[0105] Therefore, in this embodiment of the present invention, referring to Figure 28 below, the pump body 60 is generally, The virtually complete expansion configuration before pump operation, The contraction and expansion configuration during pump operation, The "vertical" effective contraction configuration after achieving a given level of negative pressure through pump operation, After achieving a given level of negative pressure, there is a "horizontal" effective contraction configuration in the case of negative pressure decay, even if the decay is not sufficient to cause a binary state transition of the pump body to an effective fully expanded configuration, A substantially complete expansion configuration after the decay of negative pressure below a given level, It will be a tightening.

[0106] Furthermore, after transitioning to a virtually fully expanded configuration, the desired negative pressure can be re-established by a new pump operation.

[0107] NPWT bandage including canister for collecting exudate In some situations, wounds can produce a significant amount of exudate. In these situations, it is desirable for negative pressure wound therapy (NPWT) bandages to include a canister for collecting the exudate.

[0108] Therefore, for example, referring to Figure 29 below, this shows a bandage 5 for negative pressure wound therapy (NPWT) including a canister 200 for collecting exudate. In this embodiment of the invention, the output of the atmospheric-side one-way valve 95 of the pump assembly 15 is directed towards the interior 205 of the canister 200 so that the exudate 210 collects in the canister 200. In one embodiment of the invention, the canister 200 includes an opening covered by a membrane 215, which is gas-permeable but not fluid-permeable so that gases can escape from the canister 200 while liquids are trapped inside the canister 200.

[0109] In another embodiment of the present invention, referring hereafter to Figure 30, the canister 200 may be disposed between the wound chamber and the wound-side one-way valve 90 of the pump assembly 15. More specifically, in this embodiment of the invention, the interior 205 of the canister 200 is in fluid communication with the wound chamber and also with the wound-side one-way valve 90 of the pump assembly 15, so that the pumping operation of the pump assembly 15 generates negative pressure inside the canister 200 and consequently inside the wound chamber. The canister 200 preferably includes the aforementioned membrane 215 (which is gas-permeable but not liquid-permeable) adjacent to the wound-side one-way valve 90 of the pump assembly 15, so that gas can escape from the canister 200 while liquid is trapped inside the canister 200 and does not enter the pump assembly 15.

[0110] In yet another embodiment of the present invention, referring hereafter to Figure 31, the canister 200 is disposed between the wound chamber and the wound-side one-way valve 90 of the pump assembly 15, similar to the configuration in Figure 30, except that the pump assembly 15 is mounted on the canister 200.

[0111] Naturally, the canister 200 may be integrally formed with the pump body 60, or it may be formed separately from the pump body 60 and only fluidly connected to the pump body 60. In either case, it is preferable that the canister 200 is attached to a part of the negative pressure wound therapy (NPWT) bandage 5 and moves together with the rest of the bandage.

[0112] Furthermore, if necessary, the canister 200 may contain an absorbent or superabsorbent material for absorbing exudate aspirated from the wound chamber (or one or more of its inner surfaces may be coated with such material). In a non-limiting example, the canister 200 may contain an absorbent or superabsorbent crystal, hydrophilic colloid, or gel-forming material (or one or more of its inner surfaces may be coated with such material).

[0113] The canister 200 may be used in conjunction with any of the pump assemblies disclosed herein. As a non-limiting example, the canister 200 may be used with the pump assemblies 15 shown in Figures 1 to 4, 17 to 20A, 21 to 25, 26 to 28, and the like.

[0114] NPWT bandages including Luer lock for suction attachment In some situations, it may be desirable to configure the negative pressure wound therapy (NPWT) bandage 5 in a larger size to cover a large wound chamber. This can be achieved by increasing the size of the membrane (or sheet) 10. However, increasing the size of the pump assembly 15 is generally undesirable, as it is desirable to maintain a low profile that does not impede use. Conversely, increasing the size of the membrane (or sheet) 10 while maintaining the size of the pump assembly 15 may be clinically undesirable, as it may require more pump compressions to aspirate a large wound chamber to the correct negative pressure level. In other words, increasing the size of the membrane (or sheet) 10 while maintaining the size of the pump assembly 15 would necessitate an increase in the number of pump compressions required to establish the correct negative pressure level in the wound chamber. Therefore, clinical considerations regarding the size of the pump assembly and the number of pump compressions used to establish the correct negative pressure level in the wound chamber may actually limit the size of the membrane (or sheet) 10.

[0115] To address this, the negative pressure wound therapy (NPWT) bandage 5 may be configured to be connected to a suction source, and by applying the suction source to the NPWT bandage 5, the correct negative pressure level can be established in the wound chamber without the need to compress the pump body 60. As a non-limiting example, referring to Figure 32 below, the NPWT bandage 5 may include half of the Luer lock 300 and the suction line 305 may include the other half of the Luer lock 310, so that the suction line 305 can be fluidly connected to the atmospheric port 87 of the pump body 60. If the other end 315 of the suction line 305 is connected to a functional suction source 320, the suction source 320 can apply suction to the pump body 60. Then, as this suction is automatically applied to the wound chamber, the suction source 320 can establish negative pressure in the wound chamber.

[0116] Importantly, when the correct negative pressure level is established in the wound chamber, the walls of the pump body 60 will contract as described above. Therefore, even when the suction source 320 is used to generate negative pressure in the wound chamber, the NPWT bandage 5 still acts as a visual indicator of when the correct negative pressure level has been established in the wound chamber. This is because when the correct negative pressure level is established in the wound chamber, the pump assembly 15 transitions from its substantially fully inflated configuration to its substantially fully deflated configuration.

[0117] After an appropriate negative pressure level is established in the wound chamber by using the suction source 320, the suction line 305 can be cut from the NPWT bandage 5.

[0118] Subsequently, if the negative pressure level in the wound chamber decreases, the correct negative pressure level in the wound chamber can be re-established by using the pump assembly 15 to compress the pump body 60 or reconnect the NPWT bandage 5 to the suction source 320.

[0119] In the preferred embodiment of the present invention described above, the NPWT bandage 5 includes half of the Luer lock, and the suction line 305 includes the remaining half of the Luer lock. However, the present invention is not limited to the use of Luer lock connections, and other types of fluid connectors may be used for connecting the suction line 305 to the pump assembly 15.

[0120] As described above, the NPWT bandage 5, through its transition from a substantially fully inflated configuration to a substantially fully deflated configuration, serves as a visual indicator of the timing for establishing the appropriate negative pressure level in the wound chamber.

[0121] Importantly, according to another feature of the present invention, by modifying the configuration of the notches 105 of the pump body 60, the NPWT bandage 5 also functions as a pressure limiter, preventing the negative pressure level established by the suction source 320 in the wound chamber from becoming too high. This is achieved by forming each of the notches 105 as two interrupted notches 105A and 105B, with the full-thickness sidewalls 65C positioned between these two interrupted notches 105A and 105B (see Figure 33). As a result of this configuration, when the correct negative pressure level is established in the wound chamber and the pump body 60 is transitioning from its substantially fully expanded configuration to its substantially fully contracted configuration, the full-thickness sidewalls 65C facing each other in the diametrically opposed direction of the pump body 60 move radially inward and engage with each other, thereby sealing the inner chamber 70 of the pump body 60 (see Figure 34). Therefore, the suction source 320 does not need to apply suction to the wound chamber separately. In this way, the NPWT bandage 5 also functions as a pressure limiter, preventing the negative pressure level established by the suction source 320 in the wound chamber from becoming too high.

[0122] The Luer lock 300 may be used with any of the pump assemblies disclosed herein. As a non-limiting example, the Luer lock 300 may be used with the pump assemblies 15 shown in Figures 1 to 4, 17 to 20A, 21 to 25, 26 to 28, 29 to 31, and the like.

[0123] The wound chamber has a lateral extension section, and the pump assembly is in fluid communication with the lateral extension section, so that the NPWT bandage is offset laterally from the wound while maintaining fluid communication with the wound. In some situations, it may be desirable to offset the pump assembly laterally from the wound while maintaining fluid communication with the wound. More specifically, for negative pressure wound therapy (NPWT) bandages with a pump assembly positioned directly above the wound being treated, complex anatomical regions with more intricate shapes present challenges. Therefore, by providing an NPWT bandage in which the wound chamber has a laterally extended portion and the pump assembly is in fluid communication with the laterally extended portion, the pump assembly may be offset laterally from the wound while maintaining fluid communication with the wound.

[0124] As a non-limiting example, such a configuration may position the NPWT bandage on the patient's physiology such that, when used for treating a wound in the groin, the main portion of the wound chamber covers the wound and the lateral extension of the wound chamber extends along the curve of the thigh, allowing the pump assembly to be positioned at the top of the upper leg, which is a more stable and less complex anatomical region for supporting the pump assembly.

[0125] As another non-limiting example, when used to treat a wound on the patient's back, the NPWT bandage may be positioned on the patient's biomechanism such that the main portion of the wound chamber covers the wound on the patient's back, and the lateral extension of the wound chamber extends along the curve of the patient's torso, allowing the pump assembly to be positioned on the anterior side of the patient for easier access.

[0126] NPWT bandages may be available with a variety of different wound chamber configurations and pump arrangements to suit the needs of various applications.

[0127] Referring to Figures 35 to 38 below, these show bandages 5 for negative pressure wound therapy (NPWT), in which the wound chamber has a lateral extension and the pump assembly is in fluid communication with the lateral extension, so that it is offset laterally from the wound while maintaining fluid communication with the wound.

[0128] More specifically, the NPWT bandage 5 shown in Figures 35-38 comprises a membrane 10 and a pump assembly 15. The membrane 10 includes a first portion 405 positioned above the wound and a second portion 410 extending laterally from the wound and supporting the pump assembly 15 at an anatomical position spaced apart from the wound.

[0129] In this embodiment of the invention, the membrane 10 is substantially similar to the membrane 10 with the configuration shown in Figures 21 to 34, in that it includes a lower skin-contact polyurethane layer 110, an intermediate foam layer 120 disposed above the lower skin-contact polyurethane layer 110, and an upper polyurethane layer 125 disposed above the intermediate foam layer 120 and the lower skin-contact polyurethane layer 110. In a preferred embodiment of the present invention, the upper polyurethane layer 125 is formed from a substantially air-impermeable material. The outer peripheries of the upper polyurethane layer 125 and the lower skin-contact polyurethane layer 110 are fixed to each other, trapping the intermediate foam layer 120 between them.

[0130] However, in this configuration (i.e., the configuration shown in Figures 35 to 38), a central opening 115 is formed in the first portion 405 of the lower skin-contact polyurethane layer 110 of the membrane 10, and an opening 130 is formed in the second portion 410 of the upper polyurethane layer 125 of the membrane 10. The intermediate foam layer 120 is in fluid communication with the central opening 115 of the first portion 405 and the opening 130 of the second portion 410. Thus, when the NPWT bandage 5 is attached to a biological structure with its central opening 115 facing above the wound, the membrane 10 forms a wound chamber, which is largely determined by the configuration of the intermediate foam layer 120. This wound chamber generally comprises (i) a main portion covering the central opening 115 of the first portion 405, and (ii) a lateral extension extending from the main portion of the wound chamber to the pump assembly 15.

[0131] Furthermore, the pump assembly 15 is attached to the upper polyurethane layer 125 so that the wound-side passage 80 of the pump assembly 15 can access the fluid (e.g., air, liquid, etc.) in the laterally extended portion of the wound chamber and, consequently, the fluid in the main portion of the wound chamber (through the porous cells of the intermediate foam layer 120) to remove the fluid from the wound site.

[0132] In the exemplary use of the NPWT bandage 5 shown in Figures 35-38, the NPWT bandage is positioned on the patient's biostructure such that the main portion of the wound chamber covers the wound and the lateral extension portion of the wound chamber extends along the patient's biostructure, allowing the pump assembly to be offset laterally from the wound (for example, to be positioned in another location that is more stable, less complex in shape, and / or more easily accessible to the patient). The use of the NPWT bandage 5 may also allow a fluid (e.g., air, liquid, etc.) to enter the main portion of the wound chamber from the wound through the central opening 115 and through the lateral extension portion of the wound chamber (e.g., the porous cells of the intermediate foam layer 120) into the pump assembly 15 through the opening 130 of the second portion 410 of the upper polyurethane layer 125 of the membrane 10.

[0133] Furthermore, the NPWT bandage 5 shown in Figures 35-38 may be used in other complex or mobile wound locations, including, but not limited to, the foot (e.g., diabetic foot ulcers), ankle, knee, shoulder, or hip joints (after joint surgery, ligament repair, arthroscopic surgery, joint replacement, etc.), arm (forearm or upper arm), neck, head, spine, or back (the main part of the wound chamber may be positioned above the wound, and the pump assembly 15 may be positioned in the front of the body). In each of these wound locations and other wound locations, the anatomical location of the wound may present challenges for wound dressings with integrated pinch-type pump assemblies due to the composition of the biological structure, the mobility of the anatomical position, the radius of curvature at the anatomical position, or the location of the wound (which may not be easily visible or manually accessible by the patient). Importantly, in a bandage for NPWT formed according to the present invention, the wound chamber is provided with a laterally extended portion, and the pump assembly is in fluid communication with the laterally extended portion, so that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound, thereby allowing the pinch-type pump assembly to be positioned in an easily accessible and physically stable anatomical location while still maintaining air / fluid communication with the wound.

[0134] This new NPWT bandage can include any number of shapes, including, but not limited to, the following: 1. A wound chamber having transverse extensions of varying lengths (e.g., short transverse extensions, long transverse extensions, etc.) (where the transverse extensions coincide with the center of the dressing, and the pinch-type pump assembly is oriented at any angle with respect to the centerline of the dressing). 2. A wound chamber having transverse extensions of varying lengths (e.g., short transverse extensions, long transverse extensions, etc.) (where the transverse extensions are positioned off-center from the dressing's centerline).

[0135] As a non-limiting example, Figures 39 to 42 show an alternative configuration of bandage 5 for negative pressure wound therapy (NPWT), in which the lateral extension of the wound chamber has a different length than that shown in Figures 35 to 38.

[0136] As another non-limiting example, Figures 43–46 show an alternative configuration of bandage 5 for negative pressure wound therapy (NPWT), in which the pinch-type pump assembly extends perpendicular to the axis of the lateral extension of the wound chamber.

[0137] As yet another non-limiting example, with reference to Figure 46A, the second portion 410 of the wound chamber may extend parallel to and offset from the first portion 405 of the wound chamber (in contrast to being positioned adjacent to one end of the first portion 405 of the wound chamber, as shown in the configurations of Figures 35-38, 39-42, and 43-46). The pump assembly 15 is attached to the second portion 410 to be in fluid communication with the wound chamber (similar to what has been described with respect to the configurations of Figures 35-38, 39-42, and 43-46), but in the configuration shown in Figure 46A, it extends substantially parallel to the first portion 405 of the wound chamber. Furthermore, with the configuration shown in Figure 46A, the placement shape of the negative pressure wound therapy (NPWT) bandage 5 may be closer to a "square" (meaning the length and width of the bandage are equal) than to a "rectangle" (meaning the length of the bandage is substantially greater than the width of the bandage) as shown in the configurations of Figures 35-38, 39-42, and 43-46.

[0138] If necessary, the notches 105 formed on the pump body 60 of the pump assemblies shown in Figures 17 to 20 and / or the notches 105 formed on the pump body 60 of the pump assemblies shown in Figures 26 to 28 may similarly be formed on the pump bodies of the NPWT bandages 5 shown in Figures 35 to 38, 39 to 42, and 43 to 46, respectively. Furthermore, if necessary, a canister 200 may be used with the pump assemblies of the NPWT bandages 5 shown in Figures 35 to 38, 39 to 42, and 43 to 46. Also, if necessary, a Luer lock 300 may be used with the pump assemblies of the NPWT bandages 5 shown in Figures 35 to 38, 39 to 42, and 43 to 46.

[0139] A bandage for negative pressure wound therapy (NPWT) to cover a wound, comprising a transparent top layer that traps a foam layer against the wound, the foam layer having a series of windows that (i) allow direct visualization of the wound and (ii) provide criteria along the length of the bandage to indicate whether the bandage needs to be changed, and further comprising a periphery serration on the foam layer to allow the bandage to conform to curved wounds, for use with NPWT. The above description discloses a variety of negative pressure wound therapy (NPWT) bandages that cover the wound and help prevent wound infection by applying negative pressure to the wound. The NPWT bandages disclosed in the above description generally comprise (i) a membrane 10 positioned above the wound, and (ii) an on-board pump assembly 15 for applying and maintaining negative pressure at the wound site.

[0140] As shown in the configurations in Figures 21 to 46, the membrane 10 generally includes (i) a lower skin-contact polyurethane layer 110 having an opening 115 positioned above the wound, (ii) an intermediate foam layer 120 positioned above the opening 115 of the lower skin-contact polyurethane layer 110 so as to be in contact with the wound, and (iii) an upper polyurethane layer 125 positioned above the intermediate foam layer 120 and the lower skin-contact polyurethane layer 110. The outer periphery of the upper polyurethane layer 125 and the lower skin-contact polyurethane layer 110 are fixed to each other, trapping the intermediate foam layer 120 between them, and an adhesive for adhering the membrane 10 to the patient's skin is provided on the lower skin-contact polyurethane layer 110.

[0141] The pump assembly 15 can be positioned with its center above the wound (see the pump assembly 15 shown in the embodiments of Figures 1 to 25), or it can be offset laterally from the wound (see the pump assembly 15 shown in the embodiments of Figures 35 to 46).

[0142] Exudate is frequently released from the wound site, especially considering the negative pressure applied to the wound. In many cases, it is desirable to obtain an indicator of the amount of exudate produced by the wound. This is because the more exudate produced, the more frequently the bandage may need to be changed (for example, because the bandage may become saturated with exudate, or because the exudate may reach the pump, leading to a decrease in pump function and / or leakage of exudate from the pump).

[0143] Therefore, a new bandage is provided below for use with types of wounds that may release exudate. More specifically, with reference to Figures 47, 48, and 49 below, these show a bandage 500 positioned above a wound that may release exudate. The bandage 500 is similar to the NPWT bandage disclosed in the above description, except that the upper polyurethane layer 125 of the membrane 10 is replaced with an upper layer 505, and the intermediate foam layer 120 of the membrane 10 is replaced with a foam layer 510.

[0144] More specifically, the upper layer 505 of the bandage 500 is formed from a transparent material (e.g., a film). The transparent upper layer 505 of the bandage allows an observer to see through the upper layer of the bandage and also observe the foam layer 510 that covers the wound (and absorbs exudate).

[0145] The foam layer 510 (see Figures 47-55) is provided with a series of windows 515 extending through the foam layer. The windows 515 allow for direct visualization of the wound and provide a guideline along the length of the bandage indicating whether the bandage needs to be replaced. Note that in Figures 50 and 53-55, only the foam layer 510 of the bandage 500 is shown for clarity of explanation.

[0146] More specifically, referring to Figures 51 and 52 below, visualization of the foam layer 510 through the transparent upper layer 505 allows the observer to visualize whether a large amount of exudate has transferred from the wound into the foam layer (the exudate is usually yellowish and therefore easily visible against the base color of the foam (preferably white, light gray, etc.)), and the windows 515 provide a reference point extending along the length of the bandage (for example, each window is a "marker line" along the "ruler" of the bandage). The amount of exudate released by the wound is reflected by the amount of foam indicating the presence of exudate (which can be quantified by identifying the portion of the foam layer 510 showing exudate and counting the number of windows adjacent to the area of ​​the foam layer 510 showing exudate). When the number of windows adjacent to the area of ​​the foam layer 510 showing exudate along the length of the foam layer 510 reaches a certain number, the observer can determine the amount of exudate coming out of the wound and decide whether to change the bandage. As a non-limiting example, if the saturation level of the foam layer 510 is less than 50% (as shown in Figure 51, which shows that three out of seven windows are adjacent to the area of ​​the foam layer 510 showing exudate 518), the bandage may be left in place on the wound. However, if the saturation level of the foam layer 510 is greater than 50% (as shown in Figure 52, which shows that four or more windows are adjacent to the area of ​​the foam layer 510 showing exudate 518), the bandage may be replaced. As another non-limiting example, if the area of ​​the foam layer 510 surrounding the window closest to the pump shows the presence of exudate, the decision may be made to replace the bandage to prevent the exudate from reaching the pump.

[0147] In a preferred embodiment, the bandage 500 may be provided with markings 520 along the length of the bandage. The markings 520 may be formed on the transparent upper layer 505 and / or the foam layer 510 (see Figures 50 to 55). As seen in Figures 53 and 54, the use of markings 520 in combination with a window 515 of the foam layer 510 may allow healthcare professionals to align the bandage 500 along the wound line 525 when applying the bandage to the wound.

[0148] If necessary, a corrugated edge or periphery saw 530 may be formed around the foam layer 510 (see Figures 47-55). As shown in Figure 55, the corrugated edge or periphery saw 530 allows for some curvature of the bandage 500 when applied to the skin surface, enabling the bandage 500 to be positioned above a non-linear incision. Therefore, it is important to note that the portion of the bandage 500 positioned above the wound should not be excessively curved. Excessive curvature of the bandage can cause wrinkles, potentially leading to a failure of the seal around the wound chamber. The degree of curvature of the bandage that can be accommodated without impairing the function of the bandage is determined by several factors, including, but not limited to, the size and shape (width and depth) of the periphery saw 530 in the foam layer 510, the deformability of the upper layer 505, and the deformability of the lower skin-contact polyurethane layer 110. If necessary, periphery serrations may also be formed on the upper layer 505 and / or the lower skin-contact polyurethane layer 110 to increase the degree of curvature that the bandage can accommodate (for example, when placing the bandage above a non-linear incision, the degree of curvature that the bandage can accommodate may be increased without impairing the airtight seal formed with the skin by reducing the "wrinkles" in the upper layer 505 and the lower skin-contact polyurethane layer 110).

[0149] In one embodiment of the present invention, as shown in Figures 47, 48, and 49, the bandage 500 is preferably a negative pressure wound therapy (NPWT) bandage including a mounted pump assembly 15, in which the pump assembly 15 is laterally offset from the bandage 500, and this configuration is substantially the same as the configuration of the NPWT bandage shown in Figures 35 to 37. However, if necessary, the transparent upper layer 505, window 515, marking 520, and peripheral sawtooth 530 may be provided in other NPWT bandages having a laterally offset pump assembly, such as the NPWT bandages shown in Figures 39 to 42 and / or the NPWT bandages shown in Figures 43 to 46.

[0150] In another configuration of the present invention, as shown in Figures 56 and 57, the bandage 500 is a negative pressure wound therapy (NPWT) bandage including a mounted pump assembly 15, with the pump assembly 15 positioned above a portion of the upper layer 505 and the foam layer 510.

[0151] In yet another configuration of the present invention, the bandage 500 is configured to be connected to a pump or another suction source (e.g., wall suction) located away from the bandage.

[0152] Furthermore, this novel bandage may be used without applying negative pressure to the wound. As a non-limiting example, as shown in Figures 58 and 59, the bandage 500 may omit connections to an onboard pump and / or a pump or another suction source located away from the bandage (e.g., wall suction). In this embodiment of the invention, the bandage 500 can essentially be used as a general-purpose bandage.

[0153] In other configurations of the present invention, the lower skin-contact polyurethane layer 110 of the bandage 500 may be omitted, and the upper layer 505 may be provided with (i) an adhesive for attaching the foam layer 510 to the upper layer 505, and (ii) an adhesive for adhering the upper layer 505 to the patient's skin. As a non-limiting example, the configurations in Figures 47 to 55 may omit the lower skin-contact polyurethane layer 110 of the bandage 500, the configurations in Figures 56 and 57 may omit the lower skin-contact polyurethane layer 110 of the bandage 500, and the configurations in Figures 58, 59, and 60 may omit the lower skin-contact polyurethane layer 110 of the bandage 500.

[0154] Furthermore, it should be noted that the lower skin-contact polyurethane layer 110 may be omitted from any of the NPWT bandages shown in Figures 21 to 46, and the upper polyurethane layer 125 may be provided with (i) an adhesive for attaching the intermediate foam layer 120 to the upper polyurethane layer 125, and (ii) an adhesive for attaching the upper polyurethane layer 125 to the patient's skin.

[0155] If necessary, the notches 105 formed on the pump body 60 of the pump assemblies shown in Figures 17 to 20 and / or the notches 105 formed on the pump body 60 of the pump assemblies shown in Figures 26 to 28 may similarly be formed on the pump bodies of the bandages 500 shown in Figures 47 to 49 and Figures 56 and 57, respectively. Furthermore, if necessary, a canister 200 may be used with the pump assemblies of the bandages 500 shown in Figures 47 to 49 and Figures 56 and 57. Also, if necessary, a Luer lock 300 may be used with the pump assemblies of the bandages 500 shown in Figures 47 to 49 and Figures 56 and 57.

[0156] Negative pressure wound therapy (NPWT) bandages for managing the biomechanisms during breast reconstruction surgery, including mastropulation and breast reduction. The above description discloses a variety of negative pressure wound therapy (NPWT) bandages that cover a wound, apply negative pressure to the wound to promote healing, and help prevent wound infection. The NPWT bandages disclosed above generally comprise (i) a membrane 10 positioned above the wound, and (ii) a mounted pump assembly 15 for applying and maintaining negative pressure at the wound site. As disclosed above, the pump assembly 15 can be centered above the wound (see the pump assembly 15 shown in embodiments of Figures 1 to 25) or offset laterally from the wound (see the pump assembly 15 shown in embodiments of Figures 35 to 46). Naturally, the present invention also addresses biological structures relating to specific mammography applications by providing and using novel NPWT bandages, as will be discussed in more detail below.

[0157] Mammaplasty (sometimes referred to as mammoplasty) is a group of various surgical procedures that can be performed to alter the shape or appearance of the breast. Specifically, mammoplasty includes procedures also known as breast fixation (surgery to lift the breast, e.g., to address a medical condition, for aesthetic purposes, etc.) and breast reduction (surgery to reduce the volume of the breast and / or alter the texture or shape of the breast, e.g., to address a medical condition, for aesthetic purposes, etc.). In such surgeries, access to the inside of the breast is usually achieved by the surgeon making an incision around the areola of the breast, continuing the incision on the surface of the breast parallel to gravity (i.e., roughly in a straight line), and then making two incisions on the underside of the breast that extend laterally from the line of the initial incision, thereby forming an overall inverted T-shaped incision (sometimes referred to in the art as an "anchor pattern") (see Figure 61).

[0158] The adoption of the T-shaped incision as described above has two potential drawbacks: (i) when the incision is closed, as a result of the unique shape of the human breast, significant tissue tension exists at the point where the transverse incision of the "T" intersects the vertical incision, and (ii) there is a risk of ischemia around the areola area, which can make it difficult to visualize within a timely manner for proper treatment.

[0159] Accordingly, there is a need for a new and improved NPWT bandage that accommodates the unique shapes of the breast and areola, and facilitates the application of additional tension to closed incisions to assist in treatment, particularly in situations where negative pressure wound therapy (NPWT) bandages are used to address T-shaped incisions.

[0160] Thus, referring now to Figure 62, this shows a novel NPWT bandage 605 formed in accordance with the present invention. The NPWT bandage 605 generally comprises a membrane 610 disposed over the wound, and an on-board pump assembly 615 for applying and maintaining negative pressure at the wound site. Except as discussed in greater detail below, the membrane 610 is substantially identical to the membrane 10 described above, and the pump assembly 615 is substantially identical to the pump assembly 15 described above.

[0161] More specifically, the membrane 610 generally includes (i) a lower skin-contacting polyurethane layer 620 having an opening 625 disposed over the wound, (ii) an intermediate foam layer 630 disposed over the opening 625 of the lower skin-contacting polyurethane layer 620 so as to contact the wound, and (iii) an upper polyurethane layer 635 disposed over the intermediate foam layer 630 and the lower skin-contacting polyurethane layer 620, wherein the perimeters of the upper polyurethane layer 635 and the lower skin-contacting polyurethane layer 620 are secured to each other to trap the intermediate foam layer 630 therebetween, and an adhesive for attaching the membrane 610 to the patient's skin is provided on the lower skin-contacting polyurethane layer 620. It will be appreciated, however, that the lower skin-contacting polyurethane layer 620 may be entirely omitted as needed without departing from the scope of the present invention.

[0162] In the first embodiment of the present invention, referring now to FIGS. 62 to 64, the film 610 of the NPWT bandage 605 generally has a "lollipop" shape defined by a radially extending portion 640 and a linearly extending portion 645. The radially extending portion 640 includes at least one central viewing window 650 for viewing the nipple / areola disposed directly beneath the radially extending portion 640 (i.e., directly beneath the film 610 of the NPWT bandage 605), so that the surgeon can regularly check for the occurrence of ischemia and take corrective action as needed. The viewing window 650 is preferably formed by forming an opening in the intermediate foam layer 630 disposed between the lower skin-contacting polyurethane layer 620 and the upper polyurethane layer 635 to provide a viewing window extending through the film 610. It should be noted that, if necessary, the upper polyurethane layer 635 may be formed of a transparent material in the region of the viewing window 650 to enable visualization of the anatomy through the viewing window 650 while maintaining a fluid seal of the wound chamber directly beneath the film 610, which will be apparent to those skilled in the art in view of the present disclosure.

[0163] Referring now to FIGS. 65 to 67, these show another novel NPWT bandage 605A formed in accordance with the present invention. The NPWT bandage 605A shown in FIGS. 65 to 67 is generally similar to the embodiment of FIGS. 62 to 64, except that the pump assembly 615 is rearranged to be disposed at one end of the linearly extending portion 645 remote from the radially extending portion 640.

[0164] Next, referring to Figures 68 to 70, these show another NPWT bandage 605B formed according to the present invention. The NPWT bandage 605B shown in Figures 68 to 70 is substantially similar to the NPWT bandage 605A shown in Figures 65 to 67, but (i) includes an orthogonal extension 655 extending perpendicularly (transversely) to the longitudinal axis of the linear extension 645 opposite to the radial extension 640, and (ii) the pump assembly 615 is rotated 90° perpendicularly to the longitudinal axis of the linear extension 645 and positioned on the orthogonal extension 655. By rotating the pump assembly 615 90°, the pump assembly 615 is aligned with the horizontal axis of the patient's abdomen, allowing the patient's chest and abdomen to fold over or together with the pump assembly 615 when the patient bends forward.

[0165] Next, referring to Figures 71 to 73, these show another NPWT bandage 605C formed according to the present invention. The NPWT bandage 605C shown in Figures 71 to 73 is substantially similar to the NPWT bandage 605B in Figures 68 to 70, except that in the embodiments of Figures 71 to 73, the radially extended portion 640 of the film 610 does not include a viewing window 650.

[0166] Next, referring to Figures 74 to 76, these show another NPWT bandage 605D formed according to the present invention. The NPWT bandage 605D shown in Figures 74 to 76 is substantially similar to the NPWT bandage 605C shown in Figures 71 to 73, but the overall length of the membrane 610 is increased by the addition of a narrow linear section 660 between the linear extension section 645 and the orthogonal extension section 655. The increased length of the membrane 610 allows the pump assembly 615 to be positioned lower on the abdomen (for example, outside the area of ​​a compression garment that the patient may wear after surgery).

[0167] Next, referring to Figures 77 to 79, these show another NPWT bandage 605E formed according to the present invention. The NPWT bandage 605E shown in Figures 77 to 79 is substantially similar to the NPWT bandage 605A in Figures 65 to 67, but the radial extension 640 includes a plurality of periphery viewing windows 652. In the NPWT bandage 605E of Figures 77 to 79, it is preferable that the diameter of the central viewing window 650 is larger than the periphery viewing windows 652 arranged around the central viewing window 650.

[0168] Next, referring to Figures 80 to 82, these show another NPWT bandage 605F formed according to the present invention. The NPWT bandage 605F shown in Figures 80 to 82 is substantially similar to the NPWT bandage 605D shown in Figures 74 to 76, but the NPWT bandage 605F in Figures 80 to 82 has a central viewing window 650 and four peripheral viewing windows 652 around the central viewing window 650 provided in the radially extended portion 640.

[0169] Next, referring to Figures 83 to 85, these show another NPWT bandage 605G formed according to the present invention. The NPWT bandage 605G shown in Figures 83 to 85 is substantially similar to the NPWT bandage 605A in Figures 65 to 67, except that the viewing window 650 in the NPWT bandage 605G of Figures 83 to 85 includes an opening with a larger diameter than the viewing window 650 in Figures 65 to 67.

[0170] Next, referring to Figures 86 to 88, these show another novel and improved NPWT bandage 605H formed according to the present invention, wherein the thickness of the intermediate foam layer of the NPWT bandage is varied to increase (or decrease) the tension applied to the patient's skin beneath the membrane of the NPWT bandage.

[0171] The NPWT bandage 605H shown in Figures 86 to 88 is generally similar to the NPWT bandage 605A shown in Figures 65 to 67, but in the NPWT bandage 605H shown in Figures 86 to 88, the intermediate foam layer 630 includes a first layer 670 and a second layer 675, with the second layer 675 positioned above the first layer 670 and extending above the first layer 670 in the region of the linear extension 645.

[0172] It was found that by changing the structure (e.g., thickness) of the intermediate foam layer 630, the tension applied by the membrane 610 to the patient's skin on both sides of the wound can be increased (or decreased).

[0173] As a non-limiting example, as will be discussed in more detail below, the intermediate foam layer 630 may be provided as a composite structure including two or more layers, so that the structure (e.g., thickness) of the intermediate foam layer 630 changes, and these layers may have different thicknesses (or the same thickness) in dimensions perpendicular to the plane defined by the intermediate foam layer 630. Furthermore, if necessary, each layer of the intermediate foam layer 630 may have different length and width dimensions (i.e., dimensions perpendicular to the thickness dimension), as will be discussed in more detail below, to form a layered intermediate foam layer 630 having a "stepped" peripheral edge.

[0174] More specifically, it was found that when the NPWT bandage is positioned above the wound to form a wound chamber, increasing the thickness of the intermediate foam layer 630 by 100% (i.e., doubling the thickness of the intermediate foam layer 630) increases the lateral force applied to the biostructure by the membrane 610 by approximately 100%, and increasing the thickness of the intermediate foam layer 630 by 200% (i.e., tripling the thickness of the intermediate foam layer 630) increases the lateral force applied to the biostructure by the membrane 610 by approximately 200%. Therefore, it was found that increasing the thickness of the intermediate foam layer 630 provides a particularly useful application for the NPWT bandage 605 at wound intersections where there is significant tension in the biostructure that needs to be counteracted by strong lateral forces to maintain wound closure and achieve proper healing. As a non-limiting example, in situations where NPWT bandage 605 (and / or NPWT bandages 605A, 605B, 605C, 605D, 605E, 605F, 605G, 605H, or 605I) is used to facilitate the healing of large incisions (for example, T-shaped incisions typically formed during breast augmentation surgery, as described above), increasing the thickness of the foam layer 630 allows for greater lateral force to be applied to the wound beneath the thickened portion of the foam layer, thereby assisting wound closure and healing. Furthermore, naturally, by changing the thickness of the intermediate foam layer 630 only in specific regions of the intermediate foam layer 630, or by changing the structure of the intermediate foam layer 630 to provide regions of the intermediate foam layer 630 with different thicknesses (for example, by providing the intermediate foam layer 630 as a composite structure including two or more layers, as described above with respect to the NPWT bandage 605H), the lateral force applied by the NPWT bandage can be adjusted for different regions of the bandage.

[0175] Specifically, by forming the intermediate foam layer 630 as a composite structure comprising two or more layers, where the length and width dimensions of each layer located further from the opening 625 (along the vertical "thickness" dimension of the film) are slightly smaller than those of the preceding layer (i.e., the layer located closer to the opening 625), the resulting composite intermediate foam layer 630 includes a "stepped" perimeter extending around the intermediate foam layer 630. Providing the intermediate foam layer in a composite form with such a "stepped" perimeter offers significant technical advantages over configurations of the intermediate foam layer 630 without such a "stepped" perimeter.

[0176] More specifically, it was found that providing the intermediate foam layer 630 as a composite structure with a “staircase” perimeter suppresses and / or eliminates undesirable “tenting” of the upper polyurethane layer 635 of the membrane 605 surrounding the intermediate foam layer 630. Specifically, as the total thickness of the intermediate foam layer increases, the upper polyurethane layer 635 extends laterally outside the intermediate foam layer 630 along a tangent extending from the top of the intermediate foam layer 630 to the lower skin contact layer 620 (and / or the surface of the patient's skin if layer 620 is omitted). The open volume between the tangent of the upper polyurethane layer 635 and the intermediate foam layer 630 tends to “tent,” and as a result, blisters may form on the patient's skin in the area around the NPWT bandage. By providing an intermediate foam layer 630 having a "stepped" structure, the empty volume between the upper polyurethane layer 635 and the intermediate foam layer is partially (or substantially) filled, thereby significantly suppressing or eliminating such "tenting" (and blister formation in the patient's skin).

[0177] Referring below to Figures 89 to 91, these show another novel NPWT bandage 605I formed according to the present invention. The NPWT bandage 605I generally comprises a first bandage element 606I and a second bandage element 607I.

[0178] The first bandage element 606I is substantially identical to the aforementioned NPWT bandage 605 shown in Figures 62 to 64, except that the pump assembly 615 is omitted and the opening 608I is formed in the upper polyurethane layer 635 of the membrane 610.

[0179] The second bandage element 607I is similar to the NPWT bandage 5 described above and comprises (ii) a membrane 10 disposed above the first bandage element 606I, and (ii) a mounted pump assembly 15 for applying and maintaining negative pressure at the wound site. More specifically, as described above, the membrane 10 generally comprises (i) a lower skin-contact polyurethane layer 110 having an opening 115 disposed above the opening 608I of the first bandage element 606I, (ii) an intermediate foam layer 120 disposed above the opening 115 of the lower skin-contact polyurethane layer 110, and (iii) an upper polyurethane layer 125 disposed above the intermediate foam layer 120 and the lower skin-contact polyurethane layer 110, with the outer periphery of the upper polyurethane layer 125 and the lower skin-contact polyurethane layer 110 fixed to each other and trapping the intermediate foam layer 120 between them. However, naturally, the lower skin-contact polyurethane layer 110 may be completely omitted as needed, without departing from the scope of the present invention.

[0180] The NPWT bandage 605I is formed by positioning a second bandage element 607I directly above the first bandage element 606I. The second bandage element 607I is positioned on the first bandage element 606I so that the opening 115 of the second bandage element 607I is fluidly connected to the wound chamber defined by the opening 625 of the first bandage element 606I, thereby fluidly connecting the intermediate foam layer 630 of the first bandage element 606I to the intermediate foam layer 120 of the second bandage element 607I.

[0181] In this embodiment of the present invention, the thickness of the intermediate foam layer 630 of the first bandage element 606I and the thickness of the intermediate foam layer 120 of the second bandage element 607I may be different (or the same) as needed, without departing from the scope of the present invention. Also, as needed, the thickness of one or both of the intermediate foam layer 630 of the first bandage element 606I and the intermediate foam layer 120 of the second bandage element 607I can be changed (for example, as with the intermediate foam layer 630 of the NPWT bandage 605H).

[0182] Naturally, the benefits obtained by varying the thickness of the intermediate foam layers 630 and 120 (whether whole or partially) are equally applicable to any of the NPWT bandages described above. As a non-limiting example, the thickness of the intermediate foam layer 630 of an NPWT 605 (and / or NPWT bandages 605A, 605B, 605C, 605D, 605E, 605F, or 605G) can be changed to achieve the same benefits achieved by varying the thickness of the intermediate foam layer 630, as disclosed in Figures 86 to 91.

[0183] Referring now to Figure 92 and Figure 93, in use, the wound is closed (e.g., sutured) after a breast reconstruction procedure. The NPWT bandage 605 (and / or NPWT bandages 605A, 605B, 605C, 605D, 605E, 605F, 605G, 605H, or 605I) is applied to the wound such that the viewing window 650 receives the patient's areola. Where peripheral viewing windows 652 are provided around the central viewing window 650, these peripheral viewing windows 652 are preferably aligned with the wound extending around the patient's areola. It will be appreciated that, as shown in Figure 92, the membrane 610 is formed to be flexible so as to conform to the shape of the anatomical structure. In a preferred configuration of the present invention, the linear extension 645 of the NPWT bandage 605 extends downward into the "T" of a T-shaped wound to cover the "T" and apply tension to the tissue, holding the tissue together for optimal treatment. As shown in Figure 92 and Figure 93, when the NPWT bandage 605F of Figures 80 to 82 is applied to a wound, the pump assembly 615 is conveniently positioned away from the bandage itself (e.g., below the actual wound on the patient's body), advantageously allowing a non-intrusive arrangement of the pump assembly 615.

[0184] Variations of the Preferred Embodiments It will be understood by those skilled in the art that many additional modifications to the details, materials, steps, and arrangement of parts described and illustrated herein to explain the nature of the present invention are possible while remaining within the principles and scope of the present invention.

Claims

1. A bandage for negative pressure wound therapy (NPWT) to apply negative pressure to a wound, A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an intermediate foam layer disposed between the two, wherein an opening for fluid communication with the wound chamber is formed on the wound side, and the membrane comprises a linearly extended portion and a radially extended portion, A negative pressure source is fluidly connected to the opening in the membrane and applies negative air pressure to the wound chamber. A bandage for NPWT equipped with [unclear].

2. The NPWT bandage according to claim 1, wherein the linear extension portion has a width perpendicular to the longitudinal axis of the linear extension portion, and the radial extension portion has a diameter, wherein the diameter of the radial extension portion is greater than the width of the linear extension portion.

3. The NPWT bandage according to claim 1, wherein the radially extended portion passes through the intermediate foam layer and includes a central viewing window that enables visualization of a biological structure located directly beneath the membrane.

4. The NPWT bandage according to claim 3, wherein the atmospheric side covering the central viewing window is provided with a transparent film.

5. The NPWT bandage according to claim 3, wherein the radially extended portion further includes at least one periphery viewing window disposed around the central viewing window, passing through the intermediate foam layer and enabling visualization of a biological structure located directly beneath the membrane.

6. The NPWT bandage according to claim 1, wherein the negative pressure source comprises a pump assembly mounted on the atmospheric side of the membrane.

7. The NPWT bandage according to claim 6, wherein the pump assembly is mounted on the linearly stretched portion of the membrane.

8. The NPWT bandage according to claim 1, wherein the radially stretched portion of the film extends from the first end of the linearly stretched portion, and the orthogonal stretched portion extends from the second end of the linearly stretched portion so as to be perpendicular to the second end.

9. The NPWT bandage according to claim 8, wherein the negative pressure source is mounted on the orthogonal extension portion and is arranged perpendicular to the longitudinal axis of the linear extension portion.

10. The NPWT bandage according to claim 9, wherein the radially extended portion passes through the intermediate foam layer and includes a central viewing window that enables visualization of a biological structure located directly beneath the membrane.

11. The NPWT bandage according to claim 8, wherein the film further includes a narrow linear portion extending between the first end of the linearly extended portion and the orthogonal extended portion.

12. The NPWT bandage according to claim 11, wherein the negative pressure source is mounted on the orthogonal stretched portion of the membrane and is arranged to be perpendicular to the longitudinal axis of the linear stretched portion.

13. The NPWT bandage according to claim 11, wherein the narrow, linear extension portion is flexible and is configured to bend when the NPWT bandage is attached to a curved biological structure to conform to the biological structure.

14. The NPWT bandage according to claim 1, wherein the intermediate foam layer comprises a first layer and a second layer, the first layer of the intermediate foam layer is disposed in the linearly extended portion and the radially extended portion, and the second layer of the intermediate foam layer is disposed above a portion of the first layer that extends above the linearly extended portion, but does not extend above a portion of the radially extended portion.

15. The NPWT bandage according to claim 14, wherein the pump assembly is mounted on the linearly stretched portion of the membrane.

16. The NPWT bandage according to claim 15, wherein the first layer has a first thickness, the second layer has a second thickness, and the first thickness is greater than the second thickness.

17. The NPWT bandage according to claim 15, wherein the first layer has a first thickness, and the second layer has a second thickness, the second thickness being greater than the first thickness.

18. The NPWT bandage according to claim 15, wherein the first layer has a first thickness, the second layer has a second thickness, and the first thickness is the same as the second thickness.

19. The first layer of the intermediate foam layer includes a first peripheral edge having a first perimeter, and the second layer of the intermediate foam layer includes a second peripheral edge having a second perimeter. The NPWT bandage according to claim 14, wherein the first perimeter is larger than the second perimeter so that the intermediate foam layer includes a stepped peripheral edge.

20. The intermediate foam layer includes a plurality of layers disposed between the first layer and the second layer, The NPWT bandage according to claim 14, wherein each of the plurality of layers is larger than the second layer, but includes a perimeter in which the size decreases from the first layer to the second layer.

21. A method for applying negative pressure to a wound, The objective is to prepare a bandage for negative pressure wound therapy (NPWT), and the NPWT bandage is: A membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and an intermediate foam layer disposed between the two, wherein an opening for fluid communication with the wound chamber is formed on the wound side, and the membrane comprises a linearly extended portion and a radially extended portion, A negative pressure source is fluidly connected to the opening in the membrane and applies negative air pressure to the wound chamber. To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound. To generate negative air pressure within the wound chamber and Methods that include...

22. The method according to claim 21, wherein the wound is the result of mastoplasty, and the NPWT bandage is positioned above the wound such that the radially extended portion of the membrane is positioned above the areola.

23. A bandage for negative pressure wound therapy (NPWT) to apply negative pressure to a wound, A first membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an atmospheric side, and a first intermediate foam layer disposed between the two, wherein an opening that is in fluid communication with the wound chamber extends through the first membrane, and the first membrane comprises a linearly extended portion and a radially extended portion, A second membrane is configured to be disposed above the first membrane, and comprises a wound side, an air side, and a second intermediate foam layer disposed between the two, wherein an opening for fluid communication with the wound chamber is formed on the wound side of the second membrane, A pump assembly attached to the atmospheric side of the second membrane, which is fluidly connected to the opening in the second membrane and the opening in the first membrane, and applies negative pressure to the wound chamber. A bandage for NPWT equipped with [unclear].

24. The NPWT bandage according to claim 23, wherein the first intermediate foam layer has a first thickness, the second intermediate foam layer has a second thickness, and the first thickness is greater than the second thickness.

25. The NPWT bandage according to claim 23, wherein the first intermediate foam layer has a first thickness, and the second intermediate foam has a second thickness, the second thickness being greater than the first thickness.

26. The NPWT bandage according to claim 23, wherein the first intermediate foam layer has a first thickness, the second intermediate foam has a second thickness, and the first thickness is the same as the second thickness.

27. The NPWT bandage according to claim 23, wherein the second membrane is disposed above the linearly extended portion of the first membrane.

28. A method for applying negative pressure to a wound, The objective is to prepare a bandage for negative pressure wound therapy (NPWT), and the NPWT bandage is: A first membrane disposed above a wound and configured to form a wound chamber between itself and the wound, comprising a wound side, an air side, and a first intermediate foam layer disposed between the two, wherein an opening that is in fluid communication with the wound chamber extends through the first membrane, and the first membrane comprises a linearly extended portion and a radially extended portion, A second membrane is configured to be disposed above the first membrane, and comprises a wound side, an air side, and a second intermediate foam layer disposed between the two, wherein an opening for fluid communication with the wound chamber is formed on the wound side of the second membrane, A pump assembly attached to the atmospheric side of the second membrane, which is fluidly connected to the opening in the second membrane and the opening in the first membrane, and applies negative pressure to the wound chamber. To have, to prepare, The NPWT bandage is placed above the wound to form a wound chamber between the membrane and the wound. To generate negative air pressure within the wound chamber and Methods that include...

29. The method according to claim 28, wherein the wound is the result of mastoplasty, and the NPWT bandage is positioned above the wound such that the radially extended portion of the membrane is positioned above the areola.

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