Negative pressure wound therapy (NPWT) bandages and removable film for bandages

Abstract

A removable film for covering an adhesive disposed on a wound-side surface of a bandage, the removable film comprising: a central film portion; a peripheral film portion extending around the central film portion; and a transition zone connecting the peripheral film portion to the central film portion.

Description

[0001] applicant Guard Medical SAS Inventor Machiel van der Leest Laurence Lefebvre Reference to pending prior patent applications This patent application: (1) Claims the benefit of pending prior U.S. provisional patent application serial number 63 / 539,975, filed on September 22, 2023, by Guard Medical SAS and Machiel van der Leest et al., entitled “NEGATIVE PRESSUREWOUND THERAPY (NPWT) BANDAGE FOR ACCOMMODATING ANATOMY DURING MAMMOPLASTY, INCLUDING MASTOPEXY AND REDUCTION MAMMOPLASTY” (Attorney’s File No. GM-23 PROV); and (2) Claim the benefit of pending prior U.S. provisional patent application serial number 63 / 557,226, filed on February 23, 2024, by Guard Medical SAS and Machiel van der Leest et al., entitled “NEGATIVE PRESSUREWOUND THERAPY (NPWT) BANDAGE” (Attorney’s File No. GM-24 PROV).

[0002] The aforementioned patent application is incorporated herein by reference. Technical Field

[0003] This invention relates generally to bandages, and more specifically to negative pressure wound therapy (NPWT) bandages. Background Technology

[0004] Bandages are used to provide wound care during the healing process. More specifically, bandages typically provide a covering to protect the wound from contaminants and microorganisms during healing. Most bandages also provide a closure feature to help keep the edges of the wound tightly closed during healing. Bandages often also include gauze or similar materials to receive exudate that appears from the wound during healing.

[0005] Negative pressure wound therapy (NPWT) bandages apply negative pressure to a wound during healing. This negative pressure helps reduce the likelihood of contaminants and microorganisms entering the wound during healing, facilitates the removal of exudate from the wound during healing, and promotes beneficial biological responses at the wound site. More specifically, NPWT bandages typically include (i) an absorbent dressing configured to form a completely sealed cavity (“wound cavity”) around the periphery of the wound, (ii) a negative pressure source, and (iii) a conduit extending between the completely sealed wound cavity and the negative pressure source. As a result of this configuration, the absorbent dressing can be applied to the wound to form a completely sealed cavity around the periphery of the wound, and the negative pressure source can apply negative pressure to this completely sealed wound cavity, causing any contaminants and microorganisms present at the wound site to be drawn away from the wound, exudate to be removed from the wound, and beneficial biological responses to be promoted at the wound site.

[0006] Most NPWT bandages are part of a large, complex NPWT system, in the sense that (i) the absorbent dressing is typically quite large (e.g., they are sized to cover large open wounds), (ii) the negative pressure source is typically quite large and is formed and positioned separately from the absorbent dressing (e.g., the negative pressure source typically includes an electric suction pump or vacuum canister), and (iii) the NPWT system typically requires extensive training to use. These NPWT systems also tend to be quite expensive.

[0007] Efforts have been made to provide a small, simplified, and less expensive NPWT bandage in which the negative pressure source is integrated with the absorbent dressing. By way of example, and not limitation, efforts have been made to provide an NPWT bandage in which a manually operated suction pump is integrated into the absorbent dressing. Unfortunately, current NPWT bandages that integrate a suction pump with the absorbent dressing often suffer from several drawbacks, such as complex design and / or high cost, and / or cumbersome use, and / or bulky (including having a high profile), and / or causing additional trauma to the wound during use, and / or inefficient pump, and / or lack of a way to indicate the level of negative pressure generated, and / or lack of a way to limit the level of negative pressure generated, etc. In the latter case, it should be understood that NPWT bandages may cause trauma to the patient, such as blistering, capillary leakage, etc., in cases where excessively high negative pressure levels are generated.

[0008] Therefore, there is a need for a new and improved NPWT bandage that is simple, inexpensive, easy to use, small in size (including having a low profile), non-invasive to wounds during use, has improved pump efficiency, includes an automatic pressure indicator for indicating the level of negative pressure generated, and provides an automatic pressure limiter for limiting the level of negative pressure generated. Summary of the Invention

[0009] These and other objects of the present invention are achieved by providing and using a new and improved NPWT bandage that is simple, inexpensive, easy to use, small in size (including having a low profile), non-invasive to wounds during use, has improved pump efficiency, incorporates an automatic pressure indicator for indicating the level of negative pressure generated, and provides an automatic pressure limiter for limiting the level of negative pressure generated.

[0010] In a preferred embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage that extends through the wall structure and communicates with the wound cavity through the opening formed in the membrane; A wound-side check valve is disposed in the wound-side channel and is configured to allow fluid to flow through the wound-side channel from the wound cavity to the pump chamber, but prevent fluid from flowing through the wound-side channel from the pump chamber to the wound cavity. An atmospheric side channel, which extends through the wall structure and connects the pump chamber to the atmosphere; and An atmospheric-side check valve is provided in the atmospheric-side channel, the atmospheric-side check valve being configured to allow fluid to flow from the pump chamber to the atmosphere through the atmospheric-side channel, but to prevent fluid from flowing from the atmosphere to the pump chamber through the atmospheric-side channel; This causes the fluid in the pump chamber to be forced out of the pump chamber via the atmospheric side channel when a compressive force is applied to the wall structure of the pump body, and when the compressive force applied to the wall structure of the pump body subsequently decreases, the fluid in the wound cavity is drawn into the pump chamber through the wound side channel.

[0011] Preferably, the NPWT bandage is configured such that when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is below a predetermined threshold, the pump body of the pump assembly will exhibit a substantially fully expanded configuration, and when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is above the predetermined threshold, the pump body of the pump assembly will exhibit a substantially fully collapsed configuration.

[0012] Even more preferably, the NPWT bandage is configured such that when the pressure difference crosses the predetermined threshold, the pump body abruptly changes state between the substantially fully expanded configuration and the substantially fully collapsed configuration, and between the substantially fully collapsed configuration and the substantially fully expanded configuration, so as to effectively constitute a substantially “binary state” device.

[0013] In another preferred embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, which include: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage that extends through the wall structure and communicates with the wound cavity through the opening formed in the membrane; A wound-side check valve is disposed in the wound-side channel and is configured to allow fluid to flow through the wound-side channel from the wound cavity to the pump chamber, but prevent fluid from flowing through the wound-side channel from the pump chamber to the wound cavity. An atmospheric side channel, which extends through the wall structure and connects the pump chamber to the atmosphere; and An atmospheric-side check valve is provided in the atmospheric-side channel, the atmospheric-side check valve being configured to allow fluid to flow from the pump chamber to the atmosphere through the atmospheric-side channel, but to prevent fluid from flowing from the atmosphere to the pump chamber through the atmospheric-side channel; This causes the fluid in the pump chamber to be forced out of the pump chamber via the atmospheric side channel when a compressive force is applied to the wall structure of the pump body, and when the compressive force applied to the wall structure of the pump body subsequently decreases, the fluid in the wound cavity is drawn into the pump chamber through the wound side channel; Position the negative pressure wound therapy (NPWT) bandage on the wound to create a wound cavity between the membrane and the wound; and A compressive force is applied to the wall structure of the pump body, and then the compressive force applied to the wall structure of the pump body is reduced in order to apply negative pressure to the wound.

[0014] In another preferred embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump, the pump being carried by the membrane and including a wall cavity disposed around a pump chamber, wherein at least a portion of the wall cavity is elastic, and further, wherein the pump chamber communicates with the wound cavity through the opening formed in the membrane; No part of the pump chamber is defined by a wound.

[0015] In another preferred embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump, the pump being carried by the membrane and including a wall cavity disposed around a pump chamber, wherein at least a portion of the wall cavity is elastic, and further, wherein the pump chamber communicates with the wound cavity through the opening formed in the membrane; The pump does not apply positive pressure to the wound.

[0016] In another preferred embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump, the pump being carried by the membrane and including a wall cavity disposed around a pump chamber, wherein at least a portion of the wall cavity is elastic, and further, wherein the pump chamber communicates with the wound cavity through the opening formed in the membrane; The pump is connected to the wound cavity such that a reduction in the volume of the pump chamber does not cause a change in pressure within the wound cavity.

[0017] In another preferred embodiment of the invention, a negative pressure wound therapy (NPWT) bandage is constructed such that it also provides a negative pressure attenuation "warning status" indication.

[0018] In one embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic, and further, wherein the pump cavity communicates with the wound cavity through the opening formed in the membrane; and An atmospheric side channel extends through the wall structure to fluidly connect the pump chamber to the atmosphere; This causes the fluid in the pump chamber to be forced out of the pump chamber through the atmospheric side channel when the compressive force is applied to the wall structure of the pump body, and when the compressive force applied to the wall structure of the pump body subsequently decreases, the fluid in the wound cavity is drawn into the pump chamber through the opening formed in the membrane; When the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is below a predetermined threshold, the pump body will exhibit a substantially fully expanded configuration, thereby indicating that the negative pressure in the wound cavity is below the predetermined threshold. Conversely, when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is above the predetermined threshold, the pump body will exhibit a substantially fully collapsed configuration, thereby indicating that the negative pressure in the wound cavity is above the predetermined threshold. Furthermore, the pump body is configured to provide a visual indication that the negative pressure within the wound cavity is decreasing, but has not yet decreased to a level sufficient to fall below the predetermined threshold and cause the pump body to transition to its substantially fully expanded configuration.

[0019] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, which include: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic, and further, wherein the pump cavity communicates with the wound cavity through the opening formed in the membrane; and An atmospheric side channel extends through the wall structure to fluidly connect the pump chamber to the atmosphere; When the compressive force is applied to the wall structure of the pump body, the fluid in the pump chamber is forced to leave the pump chamber through the atmospheric side channel, and when the compressive force applied to the wall structure of the pump body subsequently decreases, the fluid in the wound cavity is drawn into the pump chamber through the opening formed in the membrane. When the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is below a predetermined threshold, the pump body exhibits a substantially fully expanded configuration, thereby indicating that the negative pressure in the wound cavity is below the predetermined threshold. Conversely, when the pressure difference between the fluid pressure in the pump chamber and atmospheric pressure is above the predetermined threshold, the pump body exhibits a substantially fully collapsed configuration, thereby indicating that the negative pressure in the wound cavity is above the predetermined threshold. Furthermore, the pump body is configured to provide a visual indication that the negative pressure in the wound cavity is decreasing, but has not yet decreased to a level sufficient to fall below the predetermined threshold and cause the pump body to transform into its substantially fully expanded configuration; Position the NPWT bandage over the wound to create a wound cavity between the membrane and the wound; and A compressive force is applied to the wall structure of the pump body, and then the compressive force applied to the wall structure of the pump body is reduced in order to apply negative pressure to the wound.

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

[0021] In one embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; Wound-side passage, the wound-side passage extending through the wall structure and communicating with the wound cavity; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; and A canister configured to be in fluid communication with the wound cavity and the pump assembly, the canister including an inner cavity for collecting exudate leaving the wound cavity; The pump assembly is configured to generate negative pressure within the wound cavity, causing exudate from the wound cavity to flow out of the wound cavity and into the inner cavity of the canister.

[0022] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, which include: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; and A canister configured to be in fluid communication with the wound cavity and the pump assembly, the canister including an inner cavity for collecting exudate leaving the wound cavity; The pump assembly is configured to generate negative pressure within the wound cavity, causing exudate from the wound cavity to flow out of the wound cavity and into the inner cavity of the canister; Position the NPWT bandage over the wound to create a wound cavity between the membrane and the wound; and A negative pressure is generated inside the wound, causing the exudate to flow from the wound into the inner cavity of the jar.

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

[0024] In one embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity via the opening in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; and A suction source, configured to be connected to the pump assembly, for establishing negative pressure within the wound cavity; Specifically, when the negative air pressure in the wound cavity is lower than a predetermined threshold, the pump body will exhibit a configuration that is essentially fully expanded, and when the negative air pressure in the wound cavity is higher than the predetermined threshold, the pump body will exhibit a configuration that is essentially fully collapsed.

[0025] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, which include: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage that extends through the wall structure and communicates with the wound cavity through the opening in the membrane; The atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; and A suction source, configured to be connected to the pump assembly, for establishing negative pressure within the wound cavity; Specifically, when the negative air pressure in the wound cavity is lower than a predetermined threshold, the pump body will exhibit a configuration of essentially complete expansion, and when the negative air pressure in the wound cavity is higher than the predetermined threshold, the pump body will exhibit a configuration of essentially complete collapse. Position the NPWT bandage over the wound to create a wound cavity between the membrane and the wound; and The suction source is connected to the pump assembly to generate negative pressure in the wound cavity.

[0026] In another embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface and an opening extending from the wound-side surface through the membrane to the atmospheric-side surface; A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity through the opening in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; and A connector for connecting a suction source to the pump assembly to establish negative pressure within the wound cavity; Specifically, when the negative air pressure in the wound cavity is lower than a predetermined threshold, the pump body will exhibit a configuration that is essentially fully expanded, and when the negative air pressure in the wound cavity is higher than the predetermined threshold, the pump body will exhibit a configuration that is essentially fully collapsed.

[0027] In another preferred embodiment of the 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 invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane comprising a first portion and a second portion, the first portion being configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the second portion being configured to extend laterally away from the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; and A pump assembly carried by the second portion of the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity through the opening in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; The pump assembly is configured to generate negative pressure within the wound cavity.

[0029] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, including: A membrane comprising a first portion and a second portion, the first portion being configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the second portion being configured to extend laterally away from the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; and A pump assembly carried by the second portion of the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure disposed around a pump cavity, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity through the opening formed in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; The pump assembly is configured to generate negative pressure within the wound cavity; The first portion of the NPWT bandage is positioned above the wound to form an oral cavity between the membrane and the wound, and the second portion of the membrane is positioned on an anatomical structure offset laterally from the wound; and Negative pressure is generated inside the wound's oral cavity.

[0030] In another preferred embodiment of the invention, a negative pressure wound therapy bandage for covering a wound is provided, the bandage comprising a transparent top layer that traps a foam layer against the wound, wherein the foam layer is provided with a series of windows that (i) allow direct observation of the wound and (ii) provide measurements along the length of the bandage to indicate whether the bandage needs to be replaced. The foam layer also includes a peripheral serrated structure that allows the bandage to conform to the curved wound. This novel negative pressure wound therapy bandage can be used with an integrated pump or with a pump located away from the bandage (or with another suction source, such as a wall suction). This novel bandage can also be used without applying negative pressure to the wound.

[0031] In one embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; The membrane includes a transparent layer and an absorbent layer, wherein the absorbent layer is disposed on the wound side of the membrane; The absorption layer includes a plurality of windows extending through it; and The plurality of windows in the transparent layer and the absorbent layer of the membrane allow observation of the wound through the membrane; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure defining a pump chamber, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity through the opening in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; The pump assembly is configured to generate negative pressure within the wound cavity.

[0032] In another embodiment of the invention, a bandage is provided for covering exudate released from a wound, the bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; The membrane includes a transparent layer and an absorbent layer, wherein the absorbent layer is disposed on the wound side of the membrane; The absorption layer includes a plurality of windows extending through it; and The plurality of windows in the transparent layer and the absorbent layer of the membrane allow observation of the wound through the membrane.

[0033] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, including: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; The membrane includes a transparent layer and an absorbent layer, wherein the absorbent layer is disposed on the wound side of the membrane; The absorption layer includes a plurality of windows extending through it; and Furthermore, the plurality of windows in the transparent layer and the absorbent layer of the membrane allow observation of the wound through the membrane; and A pump assembly supported by the membrane, the pump assembly comprising: A pump body, the pump body including a wall structure defining a pump chamber, wherein at least a portion of the wall structure is elastic; A wound-side passage extending through the wall structure and communicating with the wound cavity through the opening formed in the membrane; and An atmospheric side channel extends through the wall structure and connects the pump chamber to the atmosphere; The pump assembly is configured to generate negative pressure within the wound cavity; Position the NPWT bandage on the wound to create a wound cavity between the membrane and the wound; A negative pressure is generated within the oral cavity of the wound; and The absorbent layer of the membrane is observed to determine whether the NPWT bandage needs to be removed from the wound and replaced with a new NPWT bandage.

[0034] In another embodiment of the invention, a method for covering exudate released from a wound is provided, the method comprising: Provide a bandage, the bandage comprising: A membrane configured to be disposed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface, an atmospheric-side surface, and an opening extending from the wound-side surface to the atmospheric-side surface, the opening being in fluid communication with the wound cavity; The membrane includes a transparent layer and an absorbent layer, wherein the absorbent layer is disposed on the wound side of the membrane; The absorption layer includes a plurality of windows extending through it; and Furthermore, the plurality of windows in the transparent layer of the membrane and the absorbent layer of the membrane allow observation of the wound through the membrane; Position the bandage over the wound to create an oral cavity between the membrane and the wound; and Observe the absorbent layer of the membrane to determine whether the bandage needs to be removed from the wound and replaced with a new bandage.

[0035] In another embodiment of the invention, a removable film is provided for covering an adhesive disposed on the wound-side surface of a bandage, the removable film comprising: Central film portion; A peripheral film portion extending around the central film portion; and A transition zone that connects the peripheral film portion to the central film portion.

[0036] In another aspect of the invention, a method is provided for removing a removable film from an adhesive disposed on a wound-side surface of a bandage, the removable film comprising a central film portion, a peripheral film portion extending around the central film portion, and a transition region connecting the peripheral film portion to the central film portion, the method comprising: Pull the central film portion toward the transition zone to expose the adhesive on the wound-side surface of the bandage; Position the wound-side surface of the bandage on the wound, while the central film portion remains connected to the peripheral film portion at the transition zone; and Move the central film portion around the bandage to pull the peripheral film portion away from the bandage, thereby removing the peripheral film portion and the central film portion from the bandage.

[0037] In another embodiment of the invention, a negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound is provided, the NPWT bandage comprising: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface and an atmospheric-side surface, wherein the wound-side surface includes an adhesive for adhering the membrane to the wound, and further wherein an opening is formed in the wound-side surface; A negative pressure source, fluidly connected to the opening in the membrane, for applying negative pressure to the wound cavity; and A removable film of adhesive covering the wound-side surface of the membrane, the removable film comprising: Central film portion; A peripheral film portion extending around the central film portion; and A transition zone that connects the peripheral film portion to the central film portion.

[0038] In another embodiment of the invention, a method for applying negative pressure to a wound is provided, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, including: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface and an atmospheric-side surface, wherein the wound-side surface includes an adhesive, and further wherein an opening is formed in the wound-side surface; A negative pressure source, fluidly connected to the opening in the membrane, for applying negative pressure to the wound cavity; and A removable film of adhesive covering the wound-side surface of the membrane, the removable film comprising: Central film portion; Peripheral film portion and A transition region that connects the peripheral film portion to the central film portion; Pull the central film portion toward the transition zone to expose the adhesive on the wound-side surface of the bandage; Position the wound-side surface of the bandage above the wound, while the central film portion remains connected to the peripheral film portion at the transition zone; The central film portion is moved around the membrane to pull the peripheral film portion away from the membrane, thereby removing the peripheral film portion and the central film portion from the membrane; and The pump assembly is used to generate negative pressure in the wound cavity. Attached Figure Description

[0039] These and other objects and features of the invention will be more fully disclosed or become apparent from the following detailed description of preferred embodiments of the invention, which are described in conjunction with the appendix. Figure 1 For consideration, the same reference numerals in the accompanying drawings refer to the same parts, and further, wherein: Figure 1-4 This is a schematic diagram illustrating a new and improved NPWT bandage formed according to the present invention, wherein... Figure 2 and Figure 3 It is a exploded diagram; Figure 4A The schematic diagram shows that for two wound chambers of different sizes (i.e., a 7.5 mL wound chamber and a 15 mL wound chamber), the maximum negative pressure can be established using (i) a deformable pump body with two check valves (where one check valve is provided on either side of the deformable pump body) and (ii) a deformable pump body with a single check valve (note: in Figure 4A In the comparison shown, the volume of the pump chamber of the deformable pump body with one check valve is the same as the volume of the pump chamber of the deformable pump body with two check valves. Figure 5 and Figure 6 The schematic diagram shows Figure 1-4 The pump body of the pump assembly of the NPWT bandage shown is in a configuration that is essentially fully expanded. Figure 5 ) and its essentially completely collapsed configuration ( Figure 6 ); Figure 7 The schematic diagram shows Figure 1-4 The pump body of the pump assembly of the NPWT bandage shown suddenly changes state between its substantially fully expanded configuration and its substantially fully collapsed configuration. Figure 8The schematic diagram illustrates how the pump body of the pump assembly of the prior art NPWT bandage gradually changes state between its substantially fully expanded configuration and its substantially fully collapsed configuration. Figure 9-16 The schematic diagram shows Figure 1-4 The exemplary uses of the new and improved NPWT bandages shown are illustrated (note that in...). Figure 11 and 14 In -16, for clarity, the removable cover 100 has been removed from the diagram (see below)); Figure 17-20 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 20A The schematic diagram shows how the pump body configuration changes during use (note that in...). Figure 20A (Only the outer boundary of the pump's sidewall 65 is shown, and for clarity, the pump's flange 75 and neck 77 are omitted). Figure 21-25 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 26 and 27 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention, wherein the pump body is configured such that it also provides a negative pressure attenuation "warning status" indication; Figure 28 The diagram illustrates how the pump body configuration, including a negative pressure attenuation "warning status" indicator, changes during use (note that in...). Figure 28 (For clarity, only the outer boundary of the pump sidewall is shown in the image). Figure 29 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 30 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 31 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 32 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figure 33 and Figure 34 The schematic diagram illustrates another new and improved NPWT bandage formed according to the present invention; Figures 35-38The schematic diagram illustrates another novel and improved NPWT bandage formed according to the present invention, wherein the wound cavity includes a lateral extension and wherein a pump assembly is in fluid communication with the lateral extension, such that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound. Figures 39-42 The schematic diagram illustrates another novel and improved NPWT bandage formed according to the present invention, wherein the wound cavity includes a lateral extension and wherein a pump assembly is in fluid communication with the lateral extension, such that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound. Figures 43-46 The schematic diagram illustrates another novel and improved NPWT bandage formed according to the present invention, wherein the wound cavity includes a lateral extension and wherein a pump assembly is in fluid communication with the lateral extension, such that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound. Figure 46A The schematic diagram illustrates another novel and improved NPWT bandage formed according to the present invention, wherein the wound cavity includes a lateral extension and wherein a pump assembly is in fluid communication with the lateral extension, such that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound. Figure 47 , 48 The schematic diagram of 49 illustrates another novel and improved NPWT bandage formed according to the present invention, wherein the bandage includes a transparent top layer that captures a foam layer against the wound, wherein the foam layer is provided with a series of windows that (i) allow direct observation of the wound and (ii) provide a measurement along the length of the bandage to indicate whether the bandage needs to be replaced, and further wherein the foam layer also includes a peripheral serrated structure that allows the bandage to conform to the curved wound. In this form of the invention, the NPWT bandage includes an integrated pump that is offset laterally from the wound. Figure 50 The schematic diagram shows Figure 47 , 48 Further details of the foam layer 49; Figure 51 and Figure 52 The schematic diagram shows in Figure 47 Various levels of exudate in the foam layer of the bandage; Figures 53 and 54 illustrate how windows in the foam layer allow medical personnel to align the bandage along the wound line; Figure 55 The diagram illustrates the peripheral serrated structure formed in the foam layer, which allows the bandage to bend in order to follow the path of the curved wound; Figure 56 and Figure 57 The diagram illustrates how it can be modified. Figure 47 , Figure 48and Figure 49 NPWT bandages are used to position the integrated pump on a portion of the foam; Figure 58 , 59 The diagram with 60 shows how it can be modified. Figure 56 and 57 The NPWT bandage is designed to remove the integrated pump, thereby providing a universal bandage including a transparent top layer that captures a foam layer against the wound, wherein the foam layer is provided with a series of windows that (i) allow direct observation of the wound and (ii) provide a measurement along the length of the bandage to indicate whether the bandage needs to be replaced, and further wherein the foam layer also includes a peripheral serrated structure that allows the bandage to conform to the curved wound. Figure 61A and Figure 61B The schematic diagram illustrates an NPWT bandage comprising a novel frame release film formed according to the present invention; Figures 62-69 The diagram shows from Figure 61A and Figure 61B The NPWT bandage shown exemplifies the removal of the novel frame release film; Figure 70 The schematic diagram illustrates another novel frame release film formed according to the present invention; Figures 71-74 The schematic diagram shows Figure 70 Other aspects of novel framework release films; Figure 75 The schematic diagram illustrates the lower surface of an NPWT bandage comprising a novel frame release film formed according to the present invention; and Figure 76 and 77 The schematic diagram shows Figure 75 Other aspects of the novel framework release film. Detailed Implementation

[0040] The present invention includes providing and using a new and improved NPWT bandage that is simple, inexpensive, easy to use, small in size (including having a low profile), non-invasive to wounds during use, has improved pump efficiency, includes an automatic pressure indicator for indicating the level of negative pressure generated, and provides an automatic pressure limiter for limiting the level of negative pressure generated.

[0041] Overview of manually operated negative pressure wound therapy (NPWT) bandages More specifically, first see Figure 1-4 The image shows a manually operated negative pressure wound therapy (NPWT) bandage 5, which features improved pump efficiency, an automatic pressure indicator for indicating the level of negative pressure generated, and an automatic pressure limiter for limiting the level of negative pressure generated.

[0042] The NPWT bandage 5 generally comprises a membrane (or sheet) 10 and a pump assembly 15.

[0043] As will be discussed below, membrane 10 is configured to form a completely sealed cavity around the periphery of the wound, thus defining the wound cavity.

[0044] Furthermore, as will be discussed below, pump assembly 15 is configured to apply negative pressure to a completely sealed wound cavity, thereby drawing away any contaminants and microorganisms present at the wound site, removing exudate from the wound, and promoting beneficial biological responses at the wound site. Importantly, pump assembly 15 is designed to provide improved pump efficiency, an automatic pressure indicator for indicating the level of negative pressure generated, and an automatic pressure limiter for limiting the level of negative pressure generated, as will be discussed below.

[0045] membrane More specifically, the membrane 10 comprises a flat, planar sheet (body) 20 formed of a flexible, substantially airtight material, such as Tegaderm from 3M (also known as Minnesota Mining and Manufacturing Company), so that it can conform to the contours of the body and form a substantially airtight cavity (i.e., wound cavity) surrounding the wound periphery. The membrane 10 is characterized by a wound-side surface 25 and an atmospheric-side surface 30. The membrane 10 is also characterized by an outer periphery 35 and an inner opening 40.

[0046] Adhesive 45 is preferably disposed on the wound-side surface 25 of the membrane 10. Release liner (release paper) 50 is preferably disposed on the wound-side surface 25 and the adhesive 45 to keep the adhesive 45 covered before use.

[0047] A removable reinforcement 55 is preferably disposed on the atmospheric side surface 30 of the membrane 10. The removable reinforcement 55 facilitates manipulation of the NPWT bandage 5 (particularly the membrane 10) during removal from its aseptic packaging and during positioning the NPWT bandage around the wound. Once the NPWT bandage 5 has been secured around the wound site, the removable reinforcement 55 is removed from the membrane 10. The removable reinforcement 55 may be provided as a single element, or more preferably, as a pair of elements to facilitate removal from the membrane 10 after the NPWT bandage 5 has been secured around the wound site.

[0048] Pump assembly Pump assembly 15 includes a pump body 60, which has a generally cylindrical shape and includes sidewalls 65 and an inner cavity 70. Pump body 60 is formed of an elastic material (e.g., silicone) such that sidewalls 65 can be compressed inward by applying an external force (e.g., squeezed by a user's thumb and forefinger) and then attempt to return to their original uncompressed state when the force is removed. Pump flange 75 is preferably formed on one side of pump body 60. As will be discussed in further detail below, pump body 60 extends through an inner opening 40 of membrane 10, and the upper surface of pump flange 75 is secured to the wound-side surface 25 of membrane 10, such that pump assembly 15 is secured to and carried by membrane 10. Pump flange 75 is preferably formed of a flexible material such that it can conform (at least to a limited extent) to the contours of the body. In one form of the invention, pump body 60 and pump flange 75 are integrally formed from the same material (e.g., silicone). In a preferred embodiment of the invention, the sidewall 65 of the pump body 60 and the pump flange 75 meet at the neck 77. Figure 5 Furthermore, in a preferred embodiment of the invention, the neck 77 has a relatively small width relative to the entire diameter of the pump body 60, wherein the groove 78 extends inwardly between the membrane 10 and the pump body 60, such that the pump body 60 is mounted to the pump flange 75, but still freely radially compressed / expanded with minimal interference to the pump flange 75. A wound-side channel 80 is formed in the pump body 60 and communicates with the inner cavity 70. The wound-side channel 80 opens on the outside of the pump body 60 at a wound-side port 82. An atmospheric-side channel 85 is formed in the pump body 60 and also communicates with the inner cavity 70. The atmospheric-side channel 85 opens on the outside of the pump body 60 at an atmospheric-side port 87.

[0049] A wound-side check valve 90 is disposed in the wound-side channel 80 and configured to allow fluid to enter the inner cavity 70 through the wound-side channel 80, but to prevent fluid from leaving the inner cavity 70 through the wound-side channel 80.

[0050] An atmospheric side check valve 95 is disposed in an atmospheric side passage 85 and configured to allow fluid to exit the inner cavity 70 through the atmospheric side passage 85, but to prevent fluid from entering the inner cavity 70 through the atmospheric side passage 85.

[0051] Due to this structure, when the pump body 60 of the pump assembly 15 is manually squeezed (e.g., by applying a compressive force to the side wall 65 of the pump body 60 with the user's thumb and forefinger), the fluid (e.g., air, liquid, etc.) in the inner cavity 70 is forced out of the inner cavity 70 via the atmospheric side channel 85, and when the pump body 60 of the pump assembly 15 is subsequently released (e.g., by relaxing the compressive force applied to the side wall 65 of the pump body 60 by the user's thumb and forefinger), the fluid (e.g., air, liquid, etc.) below the wound-side surface 25 of the membrane 10 (e.g., air, liquid, etc. in the wound cavity) will be drawn into the inner cavity 70 through the wound-side channel 80 as the elastic side wall of the pump body returns to its uncompressed state.

[0052] Note that when the pump body 60 of the pump assembly 15 is manually squeezed, the one-way operation of the wound-side check valve 90 prevents fluid (e.g., air, liquid, etc.) in the inner cavity 70 from leaving the inner cavity 70 through the wound-side channel 80. And when the pump body 60 of the pump assembly 15 is subsequently released, the one-way operation of the atmospheric-side check valve 95 prevents air from the atmosphere from being drawn into the inner cavity 70 through the atmospheric-side channel 85.

[0053] Therefore, it should be understood that repeatedly manually squeezing and releasing the pump body 60 of the pump assembly 15 will apply suction to the wound cavity located below the wound-side surface 25 of the membrane 10, thereby generating negative pressure at the wound site.

[0054] It should be understood that the method of providing a pump assembly of the present invention, which utilizes two check valves (i.e., a wound-side check valve 90 and an atmospheric-side check valve 95 disposed on either side of a deformable pump body having a linear configuration) provides many significant advantages that cannot be achieved by prior art methods of providing a deformable pump body utilizing a single check valve.

[0055] More specifically, as will be discussed below, the present invention provides a method for providing a pump assembly that utilizes two one-way valves (i.e., a wound-side one-way valve 90 and an atmospheric-side one-way valve 95 disposed on either side of a deformable pump body having a linear configuration) to allow substantially the same maximum negative pressure to be established at the wound site, regardless of the size of the wound cavity. This is not feasible for prior art methods that utilize a deformable pump body employing a single one-way valve.

[0056] Furthermore, the present invention provides a method for providing a pump assembly that utilizes two one-way valves (i.e., a wound-side one-way valve 90 and an atmospheric one-way valve 95 disposed on either side of a deformable pump body 60 with a linear configuration) to allow a greater constant selected maximum negative pressure at the wound site than that achieved using a deformable pump body with a single one-way valve (which reflects prior art methods).

[0057] More specifically, Figure 4A 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) is shown using (i) a deformable pump body with two check valves (where a check valve is provided on either side of the deformable pump body) and (ii) a deformable pump body with a single check valve (note: in Figure 4A In the comparison shown, the volume of the pump chamber of the deformable pump body with one check valve is the same as the volume of the pump chamber of the deformable pump body with two check valves.

[0058] Figure 4A Many important aspects of this invention are inherent in it.

[0059] first, Figure 4A The invention demonstrates the use of a deformable pump body with two one-way valves (one valve on each side of the deformable pump body) to empty the wound cavity, thereby establishing substantially the same maximum negative pressure in the wound cavity regardless of its size (i.e., approximately -150.0 mm Hg for a 7.5 mL wound cavity and approximately -150.0 mm Hg for a 15 mL wound cavity), whereas a deformable pump body with a single one-way valve would not (i.e., approximately -80.0 mm Hg for a 7.5 mL wound cavity and approximately -50.0 mm Hg for a 15 mL wound cavity). Therefore, the NPWT bandage of the present invention allows substantially the same maximum negative pressure to be established at the wound site, regardless of the size of the wound cavity, unlike prior art NPWT bandages.

[0060] This unique feature of the present invention is clinically important because (i) it is often desirable to establish a selected maximum negative pressure at the wound site (e.g., between approximately 60 mm Hg and approximately 180 mm Hg), and (ii) the volume or size of the wound cavity is often difficult to predict (e.g., due to variations in medical application, patient anatomy, etc.). Therefore, because the NPWT bandage of the present invention allows for the establishment of substantially the same maximum negative pressure at the wound site regardless of the size of the wound cavity, the present invention allows NPWT bandages to be pre-designed (e.g., during manufacturing) to establish a selected maximum negative pressure at the wound site, which is not possible with prior art NPWT bandages.

[0061] Secondly Figure 4A It has been shown that using a deformable pump body with two one-way valves (one one-way valve on each side of the deformable pump body) to empty the wound cavity results in a significantly higher maximum negative pressure established in the wound cavity (i.e., approximately -150.0 mm Hg for a 7.5 mL wound cavity and approximately -150.0 mm Hg for a 15 mL wound cavity) than the maximum negative pressure established using a deformable pump body with a single one-way valve (i.e., approximately -80.0 mm Hg for a 7.5 mL wound cavity and approximately -50.0 mm Hg for a 15 mL wound cavity). Therefore, the NPWT bandage of the present invention allows for a significantly higher maximum negative pressure to be established at the wound site.

[0062] It should also be noted that the pressure inside the inner cavity 70 of the pump body 60 is usually equal to the pressure below the wound-side surface 25 of the membrane 10 (i.e., the pressure inside the inner cavity 70 of the pump body 60 is usually equal to the pressure inside the wound cavity).

[0063] In a preferred embodiment of the invention, the pump assembly 15 further includes a removable cover 100. The removable cover 100 is configured to selectively close the atmospheric side passage 85 through which fluid flows when the removable cover 100 is inserted into the atmospheric side passage 85, thereby sealing the atmospheric side port 87.

[0064] Pump assembly 15 is mounted to membrane 10 such that pump assembly 15 is supported by membrane 10. More specifically, pump assembly 15 is mounted to membrane 10 by (i) passing pump body 60 of pump assembly 15 through inner opening 40 of membrane 10, (ii) abutting pump flange 75 upward against wound-side surface 25 of membrane 10, and then (iii) adhering pump flange 75 to wound-side surface 25 of membrane 10 (e.g., by bonding, adhesive, etc.). Note that pump assembly 15 and membrane 10 form a substantially airtight connection.

[0065] It is worth noting that the pump body 60 of the pump assembly 15 is specifically configured to provide (i) improved pump efficiency, (ii) an automatic pressure indicator for indicating the level of negative pressure generated, and (iii) an automatic pressure limiter for limiting the level of negative pressure generated, as will be discussed below.

[0066] More specifically, the pump body 60 of the pump assembly 15 is specifically configured such that the pump body abruptly changes state between (i) a substantially fully expanded configuration and (ii) a substantially fully collapsed configuration, in which the substantially fully expanded configuration, when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure is below a given threshold, has a generally circular cross-section (see [reference]). Figure 5 In the substantially completely collapsed configuration, when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure exceeds a given threshold, the sidewall 65 of the pump body 60 bends inward (see...). Figure 6 ).

[0067] Specifically, when the pressure difference between the fluid pressure inside the cavity 70 and atmospheric pressure is below a given threshold, the pump body 60 of the pump assembly 15 will exhibit a configuration of essentially full expansion. Figure 5 ), and when the pressure difference between the fluid pressure inside cavity 70 and atmospheric pressure exceeds a given threshold, the pump body 60 of pump assembly 15 will exhibit its substantially completely collapsed configuration. Figure 6 ).

[0068] It is worth noting that the pump body 60 of the pump assembly 15 is configured such that when the pressure difference between the fluid pressure within the cavity 70 and the atmospheric pressure crosses the aforementioned given threshold, the pump body 60 will be in a configuration of substantially full expansion. Figure 5 ) and its essentially completely collapsed configuration ( Figure 6 The state changes abruptly between ( ). See also Figure 7 The figure is a graph showing the relationship between the diameter of the sidewall 65 of the pump body 60 and the pressure difference between the fluid pressure and atmospheric pressure within the inner cavity 70. Therefore, the pump assembly 15 is specifically configured to essentially behave as a "binary" device—it is essentially fully expanded (…). Figure 5 ) or essentially completely collapsed ( Figure 6 In this regard, it should be understood that, as used herein, the term “substantially” binary state apparatus is intended to refer to an apparatus that tends to exhibit a substantially fully expanded state or a substantially fully collapsed state, and as used herein, the term “substantially binary state” behavior (operating characteristic) is intended to refer to the tendency of an apparatus to exhibit a substantially fully expanded state or a substantially fully collapsed state.

[0069] It is important to note that the essentially "binary" characteristic of the pump body 60 is a result of forming the pump body with a sidewall 65 having a generally circular cross-section. This imparts an "over-the-center" deformation characteristic to the pump body; that is, the sidewall of the pump body 60 has a "failure" mode and a "recovery" mode. In the "failure" mode, the sidewall of the pump body 60 abruptly changes from its substantially fully expanded configuration to its substantially fully collapsed configuration. In the "recovery" mode, the sidewall of the pump body 60 abruptly changes from its substantially fully collapsed configuration to its substantially fully expanded configuration. See [link to relevant documentation]. Figure 7 Note that the pump assembly 15 is formed such that the sidewall 65 of the pump body 60 and the pump flange 75 meet at the neck 77. Figure 5 The neck 77 has a relatively small width relative to the entire diameter of the pump body 60, and the groove 78 extends inward between the membrane 10 and the pump body 60, which has a generally circular cross-section over its substantially entire circumference, wherein the pump body 60 is freely radially compressed / radially expanded with minimal interference from the pump flange 75, so that the pump body 60 can exhibit substantially “binary state” characteristics.

[0070] It should also be noted that prior art methods of forming pump bodies with dome-shaped or square configurations do not provide abrupt changes in the pump body's state—instead, these prior art dome-shaped or square pump configurations provide a more gradual change in state between an expanding and collapsing configuration as the pressure difference between the fluid pressure within the cavity and atmospheric pressure changes. See also Figure 8 The graph shows the relationship between the diameter of the sidewall of a pump body with a dome-shaped or square configuration and the pressure difference between the pressure of the fluid inside the pump body and the atmospheric pressure.

[0071] By deliberately configuring the pump body 60 sidewall 65 of the pump assembly 15 to present this abrupt change in state, the pump assembly 15 is able to provide improved pump efficiency, an automatic pressure indicator for indicating the level of negative pressure generated, and an automatic pressure limiter for limiting the level of negative pressure generated.

[0072] More specifically, by configuring the pump body 60 of the pump assembly 15 such that when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure crosses a given threshold, the pump assembly 15 abruptly changes state between its substantially fully expanded configuration and its substantially fully collapsed configuration, and as long as the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure is below the given threshold, the pump assembly 15 effectively returns to its substantially fully expanded configuration. Therefore, as long as the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure is below the given threshold, the pump assembly 15 returns to its substantially fully expanded configuration during compression (i.e., squeezing), thus remaining fully effective when applying negative pressure to the wound cavity. This contrasts with the performance of prior art devices, in which the pump body gradually changes state between an expanded and collapsed configuration as the pressure difference between the fluid pressures within the pump assembly cavity changes, causing the pump assembly to gradually decrease in efficiency when reducing pressure within the wound cavity. This is because as negative pressure is generated in the wound cavity, the pump body gradually returns to its fully expanded configuration less and less, so the pump assembly is able to expel less and less fluid with each squeeze of the pump body. In other words, with devices using existing technology, the efficiency of the pump assembly decreases as negative pressure is generated in the wound cavity.

[0073] In a relevant manner, by configuring the pump body 60 such that when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure crosses a given threshold, the pump assembly 15 abruptly changes state between its substantially fully expanded configuration and its substantially fully collapsed configuration. The pump assembly 15 can then function as an automatic pressure indicator for indicating the level of negative pressure generated. That is, as soon as the pump body 60 of the pump assembly 15 returns to its substantially fully expanded configuration between compressions, it will be apparent to an observer that the pressure within the cavity 70 (and therefore the pressure within the wound cavity) is less than a given level. This contrasts sharply with the performance of prior art devices, in which the pump body 60 provides a gradual change of state between an expanded and collapsed configuration when the pressure difference between the fluid pressures within the cavity of the pump assembly changes. In this case, the pump assembly cannot function as an automatic pressure indicator for indicating the level of negative pressure generated.

[0074] Still in a related manner, by configuring the pump body 60 such that when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure crosses a given threshold, the pump body 60 will abruptly change state between its substantially fully expanded configuration and its substantially fully collapsed configuration. The pump assembly 15 can then function as an automatic pressure limiter to restrict the level of negative pressure generated, because once the pump body 60 presents its substantially fully collapsed configuration, the pump assembly 15 is no longer able to pump fluid from the wound cavity, effectively deactivating the pump assembly. This contrasts sharply with the performance of prior art devices, where the pump body provides a gradual change in state between an expanded and collapsed configuration as the pressure difference between the fluid pressures within the cavity changes, because the pump assembly is not effectively deactivated at a given pressure difference.

[0075] It should be understood that by changing one or more features of the pump body 60, for example by forming the sidewall 65 of the pump body 60 from a material with a specific hardness, by adjusting the thickness of the sidewall 65 of the pump body 60, by adjusting the diameter of the inner cavity 70 of the pump body 60, etc., the pressure difference required for the pump body 60 to switch between its substantially fully expanded configuration and its substantially fully collapsed configuration (i.e., the "given threshold" mentioned above) can be "adjusted" (i.e., customized) to a specific level.

[0076] Overall, it has been found that excellent therapeutic outcomes can be achieved when the pressure difference required for the pump body 60 to transition between its substantially fully expanded configuration and its substantially fully collapsed configuration (i.e., the aforementioned "given threshold") is between approximately 60 mm Hg and approximately 180 mm Hg. In other words, it has been found that the pump body 60 is in its substantially fully expanded configuration under negative pressure between approximately 60 mm Hg and approximately 180 mm Hg. Figure 5 ) and its essentially completely collapsed configuration ( Figure 6 Excellent therapeutic outcomes can be achieved when switching between the two states of the pump body 60 at lower pressures (i.e., when the pump body 60 switches at a negative pressure below about 60 mm Hg), the suction provided at the wound site is insufficient to effectively remove contaminants and microorganisms from the wound site and / or effectively remove exudate from the wound site and / or promote beneficial biological responses at the wound site. It is also believed that when the pump body 60 switches between the two states of the pump body 60 at higher pressures (i.e., when the pump body 60 switches at a negative pressure above about 180 mm Hg), the suction provided at the wound site may cause tissue trauma (e.g., blistering, capillary leakage, etc.).

[0077] In a preferred embodiment of the invention, the pump body 60 of the pump assembly 15 is configured such that when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure exceeds 80 mm Hg, the pump body abruptly transitions between its substantially fully expanded configuration and its substantially fully collapsed configuration. Thus, in this embodiment of the invention, as long as the negative pressure within the wound cavity is less than 680 mm Hg (assuming atmospheric pressure is 760 mm Hg), the pump assembly 15 returns to its substantially fully expanded configuration during pump body compression and maintains its pump efficiency while applying suction to the wound cavity. Once the negative pressure within the wound cavity exceeds 680 mm Hg (assuming atmospheric pressure is 760 mm Hg), the pump assembly 15 assumes its substantially fully collapsed configuration, acting as an automatic pressure indicator to indicate that the negative pressure level generated at the wound site has exceeded 80 mm Hg, and automatically deactivates the pump assembly 15 so that the negative pressure level generated at the wound site does not exceed 80 mm Hg.

[0078] Note that because the pump body 60 of the pump assembly 15 has a generally cylindrical configuration, the NPWT bandage 5 has a low profile.

[0079] It should also be noted that because the pump body 60 of the pump assembly 15 is configured to be squeezed between the user's thumb and forefinger, the compressive force applied to the pump body 60 is applied parallel to the skin surface, thus preventing trauma to the wound during use (i.e., during the suction process of the pump assembly 15). This contrasts sharply with prior art NPWT bandages that employ a dome-shaped configuration and require the application of compressive force to the wound.

[0080] Exemplary use In a preferred embodiment of the invention, and now see Figure 9-16 The NPWT bandage 5 is intended to be used as follows.

[0081] First, remove the NPWT bandage 5 from its box. In one form of the invention, each individual NPWT bandage 5 is contained in a separate sterile package, and multiple sterile packages are contained in one box. See also Figure 9 .

[0082] Next, remove the NPWT bandage 5 from its sterile packaging. Figure 10 ), ready to use ( Figure 11 ).

[0083] To apply the NPWT bandage 5 to the wound site, the release liner 50 is removed from the wound-side surface 25 of the membrane 10. See also Figure 12The NPWT bandage 5 is then positioned against the patient's skin, with the wound-side surface 25 of the membrane 10 positioned against the wound. The NPWT bandage 5 is then secured to the patient's skin with adhesive 45, thus forming a substantially airtight seal around the periphery of the wound. See also Figure 13 .

[0084] Note that when the NPWT bandage 5 is applied to the patient's skin, the wound-side port 82 of the wound-side channel 80 of the pump assembly 15 opens into the wound cavity.

[0085] It should also be noted that before placing the NPWT bandage 5 on the patient's skin, a layer of gauze (or other absorbent wound dressing) 102 can be placed on the wound site, such that the gauze (or other absorbent wound dressing) is positioned between the wound and the wound-side channel 80 of the pump assembly 15. In this way, exudate flowing from the wound will be absorbed by the gauze (or other absorbent wound dressing). Note that, if necessary, the gauze (or other absorbent wound dressing) 102 can be attached to (i.e., fixed to) the wound-side surface of the membrane 10, for example, during manufacturing such that the gauze (or other absorbent wound dressing) 102 is brought to the wound site by the NPWT bandage 5 and applied to the wound simultaneously with the NPWT bandage 5.

[0086] Next, with the NPWT bandage 5 secured to the patient's skin, the removable reinforcement 55 is removed from the atmospheric side surface 30 of the membrane 10. See also Figure 14 .

[0087] At this point, negative pressure can be applied to the wound cavity using an NPWT bandage 5. This is accomplished by squeezing the sidewall 65 of the pump body 60 between the user's thumb and forefinger to compress the pump body 60 into a substantially completely collapsed configuration, thereby discharging fluid (e.g., air, liquid, etc.) from the inner cavity 70 of the pump body 60 via an atmospheric side passage 85 and an atmospheric side check valve 95. See also Figure 15 Note that the presence of the wound-side check valve 90 prevents fluid in the inner cavity 70 of the pump body 60 from leaving the inner cavity 70 through the wound-side channel 80. Then, releasing the sidewall 65 of the pump body 60 allows the resilient pump body 60 to return to its substantially fully expanded configuration, thereby creating a negative pressure within the inner cavity 70 and the wound-side channel 80, causing fluid below the wound-side surface 25 of the membrane 10 (e.g., fluid within the wound cavity) to be drawn into the inner cavity 70 through the wound-side channel 80 and the wound-side check valve 90. Note that the presence of the atmospheric-side check valve 95 prevents air from entering the inner cavity 70 through the atmospheric-side channel 85.

[0088] Repeat the process of squeezing and releasing the sidewall 65 of the pump body 60 until the pump body 60 of the pump assembly 15 remains in its substantially fully collapsed configuration (i.e., the sidewall 65 of the pump body 60 is bent inward), even when the sidewall 65 of the pump body 60 is not manually compressed. See also Figure 16 When the pump body 60 of the pump assembly 15 remains in its substantially fully collapsed configuration even without manual compression of the sidewall 65, the observer knows that the pressure difference between the fluid pressure in the cavity 70 (and the wound cavity) and atmospheric pressure exceeds the desired threshold, indicating that the desired negative pressure level has been achieved at the wound site. Note that when the pump body 60 of the pump assembly 15 remains in its substantially fully collapsed configuration even without manual compression of the sidewall 65, the pump assembly 15 will be effectively deactivated because it is impossible to continue using the pump assembly when the sidewall 65 is in its substantially fully collapsed configuration.

[0089] At this point, the atmospheric side port 87 of the atmospheric side channel 85 can be sealed using a removable cover 100.

[0090] For an appropriate period of time (e.g., several days), the NPWT bandage 5 remains in place on the wound to protect it from contaminants and microorganisms during the healing process, draw exudate away from the wound, and promote beneficial biological responses at the wound site. When a leak should cause the negative pressure generated in the wound cavity to drop below a given threshold (which is obvious to an observer as the sidewall 65 of the pump body 60 returns to its substantially fully expanded configuration), the atmospheric side port 87 of the atmospheric side passage 85 can be opened (i.e., by removing the removable cap 100), and the pump assembly 15 can then be used in the manner described above to re-establish the desired negative pressure in the wound cavity (i.e., by repeatedly squeezing and releasing the sidewall 65 of the pump body 60).

[0091] When appropriate, the NPWT bandage 5 can be removed from the patient's skin by simply releasing the membrane 10 from the patient's skin.

[0092] The pump body features notches to enhance its essentially "binary" state. characteristic As described above, the pump body 60 of the pump assembly 15 is preferably specifically configured such that the pump body abruptly changes state between (i) a substantially fully expanded configuration and (ii) a substantially fully collapsed configuration, in which the substantially fully expanded configuration, when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure is below a given threshold, has a generally circular cross-section (see [reference]). Figure 5 In the substantially completely collapsed configuration, when the pressure difference between the fluid pressure within the cavity 70 and atmospheric pressure exceeds a given threshold, the sidewall 65 of the pump body 60 bends inward (see...). Figure 6 ).

[0093] As described above, this essentially "dual-state" characteristic of the pump body 60 is achieved by forming the pump body with a generally circular cross-section. This endows the pump body with "over-center" deformation characteristics, that is, it causes the sidewalls of the pump body 60 to have a "failure" mode and a "recovery" mode. In the failure mode, the sidewalls of the pump body 60 abruptly change from a substantially fully expanded configuration to a substantially fully collapsed configuration. In the recovery mode, the sidewalls of the pump body 60 abruptly change from a substantially fully collapsed configuration to a substantially fully expanded configuration. See also Figure 7 As described above, the pump assembly 15 is formed such that the sidewall 65 of the pump body 60 and the pump flange 75 meet at the neck 77. Figure 5 The neck 77 has a relatively small width relative to the entire diameter of the pump body 60, and the groove 78 extends inward between the membrane 10 and the pump body 60, which has a generally circular cross-section over its substantially entire circumference, and which is free to radially compress / radially expand with minimal interference from the pump flange 75, so that the pump body 60 can exhibit substantially “binary state” characteristics.

[0094] If necessary, pump body 60 can be modified to enhance the pump body's essentially "binary state" characteristics.

[0095] As an example rather than a limitation, see now. Figure 17-20 The notch 105 may be formed in the pump body 60 (e.g., at the "9 o'clock", "12 o'clock", and "3 o'clock" positions) to enhance the essentially "dual-state" characteristics of the pump body by further inducing the pump body 60 to exhibit only its substantially fully expanded configuration or its substantially fully collapsed configuration. Note that the more genuine "dual-state" characteristics the pump body 60 exhibits, the higher the pump efficiency, and the better the pump assembly 15 functions as an automatic pressure indicator and as an automatic pressure limiter.

[0096] Therefore, it can be seen that now see Figure 20A Pump body 60 typically has: The configuration that is almost fully expanded before suction; The configuration of collapse and expansion during the suction process; The "vertically oriented" essentially collapsed configuration after a given negative pressure level has been achieved through suction; and The configuration that is essentially fully expanded after the negative pressure has decayed to below a given level.

[0097] Furthermore, after transitioning to a configuration that is essentially fully expanded, the desired negative pressure can be re-established by pumping again.

[0098] NPWT bandages contain gauze (or other absorbent wound dressings) and utilize an improved pump assembly. See next. Figure 21-25 This illustrates another negative pressure wound therapy (NPWT) bandage 5 formed according to the present invention. Figure 21-25 The NPWT bandage 5 shown is... Figure 1-16 The NPWT bandage 5 shown Figure 17-20 The NPWT bandage shown is basically the same as the one shown, except that (i) in Figure 21-25 In the structure shown, membrane 10 comprises multiple layers containing gauze (or other absorbent wound dressing), and (ii) in Figure 21-25 In the structure shown, the pump assembly 15 has a modified structure and is fixed to the membrane 10 using a different method.

[0099] More specifically, in this form of the invention, the membrane 10 includes a lower polyurethane layer 110 having a central opening 115 for contact with the skin, an intermediate foam (or gauze or other absorbent wound dressing) layer 120 disposed above the central opening 115 of the lower polyurethane layer 110, and an upper polyurethane layer 125 disposed above the intermediate foam layer 120 and the lower polyurethane layer 110. In a preferred embodiment of the invention, the upper polyurethane layer 125 is formed of a substantially impermeable material. Furthermore, in a preferred embodiment of the invention, the upper polyurethane layer 125 and the lower polyurethane layer 110 have outer peripheries of the same size, such that the upper polyurethane layer 125 does not contact the patient's skin. The outer peripheries of the upper polyurethane layer 125 and the lower polyurethane layer 110 are secured to each other, trapping the intermediate foam layer 120 between them. The outer periphery of the intermediate foam layer 120 is (i) larger than the periphery of the central opening 115 of the lower polyurethane layer 110 in contact with the skin, and (ii) smaller than the outer periphery of both the lower polyurethane layer 110 and the upper polyurethane layer 125 in contact with the skin. In this way, when the central opening 115 of the lower polyurethane layer 110 in contact with the skin of the NPWT bandage 5 is positioned over the wound, fluid from the wound can reach the intermediate foam layer 120 through the central opening 115 of the lower polyurethane layer 110 in contact with the skin. It should be understood that the adhesive 45 is positioned on the wound-side surface of the lower polyurethane layer 110 in contact with the skin, such that a substantially airtight seal can be established around the periphery of the wound by the NPWT bandage 5 (i.e., to form the aforementioned wound cavity). An opening 130 is formed in the upper polyurethane layer 125 and overlaps with the central opening 115 of the lower polyurethane layer 110 that contacts the skin, such that the wound-side channel 80 of the pump assembly 15 can communicate (i.e., via the opening 130 in the upper polyurethane layer 125, the opening in the intermediate foam layer 120, and the central opening 115 of the lower polyurethane layer 110 that contacts the skin) fluid (e.g., air, liquid, etc.) in the wound mouth to expel it during the suction process of the pump assembly 15.

[0100] exist Figure 21-25The pump assembly 15 used in the NPWT bandage 5 is generally similar to the pump assembly 15 described above, except that it includes a pair of bases 135A and 135B for mounting the pump assembly 15 to the membrane 10. More specifically, base 135A includes one end of the pump body 60 and is adhered (e.g., by adhesive 137) to the upper surface of the membrane 10 (i.e., to the upper surface of the upper polyurethane layer 125) such that the wound-side channel 80 and the wound-side one-way valve 90 are aligned with the opening 130 in the upper polyurethane layer 125 (thus in fluid communication with the wound cavity). Base 135B includes the other end of the pump body 60 and is adhered (e.g., by adhesive 138) to the upper surface of the membrane 10 (i.e., to the upper surface of the upper polyurethane layer 125). The middle portion 140 of the pump body 60 is suspended between bases 135A and 135B and raised above the upper polyurethane layer 125 of the membrane 10, thus forming a space 145 between the middle portion 140 of the pump body 60 and the upper polyurethane layer 135 of the membrane 10. Since the middle portion 140 of the pump body 60 is not directly mounted to the membrane 10, but is suspended above the membrane 10 via bases 135A and 135B, the middle portion 140 of the pump body 60 can be formed with a truly circular cross-section, thereby enhancing the essentially "binary" characteristics of the NPWT bandage. It should be understood that the pump body 60 may include one or more of the aforementioned notches 105 to further enhance the essentially "binary" characteristics of the NPWT bandage.

[0101] Features a negative pressure attenuation "warning status" indicator. instrument NPWT bandage It has also been discovered that, if needed, pump body 60 can be configured to provide a negative pressure attenuation "warning status" indicator.

[0102] More specifically, by controlling the number, configuration, and arrangement of the notches 105, the pump body 60 can provide a "warning state" indicator to indicate that a decrease in negative pressure has occurred, although the decrease is insufficient to cause a binary state transition of the pump body (i.e., from a substantially collapsed configuration to a substantially fully expanded configuration). By way of example and not limitation, by providing a pump body with (appropriate in number, configuration, and arrangement) notches 105, the pump body can provide a "warning state" indicator (for indicating that the negative pressure has decreased to below a given level, although the decrease is insufficient to cause a binary state transition of the pump body) by: changing the pump body from its substantially collapsed configuration in a "vertical orientation" (which occurs after a given negative pressure level has been achieved) to a substantially collapsed configuration in a "horizontal orientation" (which occurs after a certain degree of negative pressure decrease has occurred, although the decrease is insufficient to cause a binary state transition of the pump body to a substantially fully expanded configuration).

[0103] Figure 26 and Figure 27An exemplary structure is shown in which a pump body having (appropriate in number, configuration and arrangement) notches 105 can provide a “warning state” indicator (for indicating that the negative pressure has decayed below a given level, although the decay is insufficient to cause a binary state transition of the pump body to a fully expanded configuration) by: changing the pump body from its “vertically oriented” substantially collapsed configuration (which occurs after a given negative pressure level has been achieved) to a “horizontally oriented” substantially collapsed configuration (which occurs after a certain degree of negative pressure decay has been present, although the decay is insufficient to cause a binary state transition of the pump body to a substantially fully expanded configuration).

[0104] Therefore, it can be seen that in this form of the invention, see now... Figure 28 Pump body 60 typically has: The configuration is almost fully expanded before suction; The configuration of collapse and expansion during suction; The "vertically oriented" essentially collapsed configuration after a given negative pressure level has been achieved through suction; A "horizontally oriented" essentially collapsed configuration after a given negative pressure level has been achieved but there is a decay of the negative pressure, although the decay is insufficient to cause a binary state transition of the pump body to a essentially fully expanded configuration; and The configuration that is essentially fully expanded after the negative pressure has decayed to below a given level.

[0105] Furthermore, after transitioning to a configuration that is essentially fully expanded, the desired negative pressure can be re-established by pumping again.

[0106] NPWT bandage with a canister for collecting exudate In some cases, wounds may produce a considerable level or a large amount of exudate. In these cases, it may be desirable for negative pressure wound therapy (NPWT) bandages to include a canister for collecting the exudate.

[0107] Therefore, for example, see now. Figure 29 The invention illustrates a negative pressure wound therapy (NPWT) bandage 5, which includes a canister 200 for collecting exudate. In this form of the invention, an atmospheric-side check valve 95 of the pump assembly 15 outputs to the interior 205 of the canister 200, thereby collecting exudate 210 within the canister 200. In another form of the invention, the canister 200 includes an opening covered by a membrane 215, wherein the membrane 215 is gas-permeable but fluid-impermeable, such that gas can escape from the canister 200, but liquid is trapped within the canister 200.

[0108] In another form of the invention, see now. Figure 30The canister 200 can be disposed between the wound cavity and the wound-side check valve 90 of the pump assembly 15. More specifically, in this form of the invention, the interior 205 of the canister 200 is in fluid communication with both the wound cavity and the wound-side check valve 90 of the pump assembly 15, such that the pump assembly 15, which is aspirating, is within the canister 200 and thus creates a negative pressure within the wound cavity. Preferably, the canister 200 includes the aforementioned membrane 215 (which is gas-permeable but liquid-impermeable) adjacent to the wound-side check valve 90 of the pump assembly 15, allowing gas to escape from the canister 200 while liquid is trapped within the canister 200 and does not enter the pump assembly 15.

[0109] In yet another form of the invention, see now. Figure 31 200 cans are similar to Figure 30 The structure is positioned between the wound cavity and the wound-side check valve 90 of the pump assembly 15, the difference being that the pump assembly 15 is mounted on top of the tank 200.

[0110] It should be understood that the canister 200 may be integrally formed with the pump body 60, or it may be separately formed from the pump body 60 and simply fluidly connected to the pump body 60. However, in any case, the canister 200 is preferably mounted to a portion of the negative pressure wound therapy (NPWT) bandage 5 such that the canister 200 moves together with the rest of the bandage.

[0111] Furthermore, if desired, the can 200 may contain (or have one or more of its internal surfaces coated with) absorbent or superabsorbent material to absorb fluid exudate draining from the wound. By way of example and not limitation, the can 200 may contain (or have one or more of its internal surfaces coated with) absorbent or superabsorbent crystals or hydrocolloids or gel-forming substances.

[0112] Tank 200 can be used with any pump assembly disclosed herein. As an example and not a limitation, tank 200 can be used with... Figure 1-4 Pump assembly 15 shown Figure 17-20A Pump assembly 15 shown Figure 21-25 Pump assembly 15 shown Figure 26-28 The pump assembly 15 shown is used together.

[0113] NPWT bandage with Luer lock for suction attachment In some cases, it may be desirable to manufacture a large-sized negative pressure wound therapy (NPWT) bandage 5 to cover a large wound cavity. This can be achieved by increasing the size of the membrane (or sheet) 10. However, increasing the size of the pump assembly 15 may not be desirable, as it is generally desirable for the pump assembly to maintain a low, non-invasive profile. Increasing the size of the membrane (or sheet) 10 while maintaining the size of the pump assembly 15 may be clinically undesirable, as that would require more pump compressions to evacuate a large wound cavity 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 has the effect of increasing the number of pump compressions required to establish the correct negative pressure level in the wound cavity. Therefore, in a practical sense, clinical considerations regarding the size of the pump assembly, and also the number of pump compressions required to establish the correct negative pressure level in the wound cavity, may limit the size of the membrane (or sheet) 10.

[0114] To address this issue, the negative pressure wound therapy (NPWT) bandage 5 can be configured to connect to a suction source, allowing the suction source to be applied to the NPWT bandage 5 to establish the correct negative pressure level in the wound cavity without requiring the compression pump 60. See now, as an example and not a limitation. Figure 32 The NPWT bandage 5 may include one half (body) 300 of the Luer lock, and the suction line 305 may include a second half (body) 310 of the Luer lock, such that the suction line 305 is fluidly connected to the atmospheric side port 87 of the pump body 60. When the other end 315 of the suction line 305 is connected to an active suction source 320, the suction source 320 can apply suction to the pump body 60. This suction is then automatically applied to the wound cavity, so that the suction source 320 can establish negative pressure in the wound cavity.

[0115] It is worth noting that when the correct negative pressure level is established in the wound cavity, the walls of the pump body 60 will collapse in the manner described above. Therefore, even when a negative pressure is generated in the wound cavity using the suction source 320, the NPWT bandage 5 still serves as a visual indicator of when an appropriate negative pressure level has been established in the wound cavity, because when an appropriate negative pressure level has been established in the wound cavity, the pump assembly 15 changes from its substantially fully expanded configuration to its substantially fully collapsed configuration.

[0116] After establishing an appropriate negative pressure level in the wound cavity using the suction source 320, the suction line 305 can be disconnected from the NPWT bandage 5.

[0117] Subsequently, if the negative pressure level in the wound cavity decreases or drops, the pump assembly 15 can be used to re-establish the correct negative pressure level in the wound cavity by compressing the pump body 60 or by reconnecting the NPWT bandage 5 to the suction source 320.

[0118] In the preferred embodiment of the invention described above, the NPWT bandage 5 includes one half of a Luer lock, and the suction line 305 includes the second half of a Luer lock. However, the invention is not limited to the use of a Luer lock connection; other types of fluid connectors can be used to connect the suction line 305 to the pump assembly 15.

[0119] As described above, the NPWT bandage 5 serves as a visual indicator of when an appropriate level of negative pressure is established in the wound cavity, i.e., by transitioning from its substantially fully inflated configuration to its substantially fully collapsed configuration.

[0120] It is worth noting that, according to another feature of the invention, by modifying the configuration of the notches 105 of the pump body 60, the NPWT bandage 5 can also function as a pressure limiter to prevent the suction source 320 from establishing an excessively high negative pressure level in the wound cavity. This is achieved by forming each notch 105 as two disconnected notches 105A, 105B, wherein a full-thickness sidewall portion 65C is disposed between the two disconnected notches 105A, 105B. See also Figure 33 As a result of this structure, when the correct negative pressure level has been established in the wound cavity, causing the pump body 60 to transition from its substantially fully expanded configuration to its substantially fully collapsed configuration, the opposing full-thickness sidewall portions 65C of the pump body 60 in the diametrical direction move radially inward and engage with each other, thereby sealing the inner cavity 70 of the pump body 60. See also Figure 34 This prevents the suction source 320 from applying any further suction to the wound cavity. In this way, the NPWT bandage 5 can also act as a pressure limiter to prevent the suction source 320 from establishing an excessively high negative pressure level in the wound cavity.

[0121] The Luer Lock 300 can be used with any pump assembly disclosed herein. As an example and not a limitation, the Luer Lock 300 can be used with... Figure 1-4 Pump assembly 15 shown Figure 17-20A Pump assembly 15 shown Figure 21-25 Pump assembly 15 shown Figure 26-28 Pump assembly 15 shown Figures 29-31 The pump assembly 15 shown is used together.

[0122] NPWT bandage, wherein the wound cavity includes a lateral extension, and wherein a pump assembly is in fluid communication with the lateral extension. This causes the pump assembly to be offset laterally from the wound while maintaining fluid communication with the wound. In some cases, it may be desirable to laterally offset (or deviate laterally from) the wound while maintaining fluid communication with it. More specifically, challenging anatomical regions with more complex geometries present challenges for negative pressure wound therapy (NPWT) bandages where the pump assembly is positioned directly above the wound being treated. By providing an NPWT bandage in which the wound cavity includes a lateral extension and the pump assembly is in fluid communication with the lateral extension, the pump assembly can be laterally offset from the wound while maintaining fluid communication with it.

[0123] As an example, and not a limitation, using such a structure, the NPWT bandage is used to treat wounds in the groin area. The NPWT bandage can be positioned on the patient's anatomy so that the main part of the wound cavity covers the wound, and the lateral extension of the wound cavity extends along the curve of the thigh, so that the pump assembly can be positioned in the upper part of the thigh, which is a more stable and relatively simple anatomical area in terms of supporting the pump assembly.

[0124] As a further example and not a limitation, the NPWT bandage is used to treat wounds on a patient's back. The NPWT bandage can be positioned on the patient's anatomy so that the main part of the wound cavity covers the wound on the patient's back, and the lateral extension of the wound cavity extends along the curve of the patient's torso so that the pump assembly can be positioned in front of the patient, where the patient can easily reach (or manipulate) it.

[0125] NPWT bandages are available in a variety of wound cavity configurations and pump placements, depending on the application.

[0126] See now Figures 35-38 The image shows a negative pressure wound therapy (NPWT) bandage 5, wherein the wound cavity includes a lateral extension and a pump assembly is in fluid communication with the lateral extension, such that the pump assembly can be laterally offset from the wound while maintaining fluid communication with the wound.

[0127] More specifically, Figures 35-38 The NPWT bandage 5 shown includes a membrane 10 and a pump assembly 15. The membrane 10 includes a first portion 405 for placement on a wound and a second portion 410 for laterally extending away from the wound and for supporting the pump assembly 15 at an anatomical location spaced apart from the wound.

[0128] Using this form of the invention, membrane 10 is generally similar to Figure 21-34The membrane 10 shown comprises a lower polyurethane layer 110 in contact with the skin, an intermediate foam layer 120 disposed on the lower polyurethane layer 110, and an upper polyurethane layer 125 disposed on the intermediate foam layer 120 and the lower polyurethane layer 110. In a preferred embodiment of the invention, the upper polyurethane layer 125 is formed of a substantially impermeable material. The outer peripheries of the upper polyurethane layer 125 and the lower polyurethane layer 110 are fixed to each other, trapping the intermediate foam layer 120 between them.

[0129] However, in this structure (i.e., Figures 35-38 In the structure shown, a central opening 115 is formed in a first portion 405 of the lower polyurethane layer 110 of the membrane 10 that contacts the skin, and an opening 130 is formed in a second portion 410 of the upper polyurethane layer 125 of the membrane 10. An 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. In this way, when the NPWT bandage 5 is adhered to an anatomical structure with its central opening 115 positioned above the wound, the membrane 10 forms a wound cavity typically defined by the intermediate foam layer 120 in this configuration. This wound cavity typically includes (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 cavity to the pump assembly 15.

[0130] The pump assembly 15 is mounted to the upper polyurethane layer 125 such that the wound-side channel 80 of the pump assembly 15 can communicate with fluid (e.g., air, liquid, etc.) in the lateral extension of the wound cavity, and further communicate with fluid in the main part of the wound cavity (i.e., through the porous unit of the intermediate foam layer 120), thereby drawing fluid away from the wound site.

[0131] exist Figures 35-38 In an exemplary use of the NPWT bandage 5, the NPWT bandage is positioned on the patient's anatomy so that the main portion of the wound cavity covers the wound, and the lateral extensions of the wound cavity extend along the patient's anatomy, allowing the pump assembly to be laterally offset from the wound, for example, positioned in a more stable and / or simpler body surface and / or more easily accessible location by the patient. The NPWT bandage 5 can then be used to apply negative pressure to the wound cavity, allowing fluid (e.g., air, liquid, etc.) to enter from the wound through the central opening 115 into the main portion of the wound cavity, through the lateral extensions of the wound cavity (e.g., through the porous units of the intermediate foam layer 120), and through openings 130 in the second portion 410 of the upper polyurethane layer 125 of the membrane 10 into the pump assembly 15.

[0132] Figures 35-38The NPWT bandage 5 can also be used in other complex or mobile wound locations, including but not limited to: the foot (diabetic foot ulcers, etc.); joints, such as the ankle, knee, shoulder, or hip (after joint surgery, ligament repair, arthroscopic surgery, joint replacement, etc.); the arm (lower or upper), neck, head, spine, or back (where the pump assembly 15 can be placed in front of the body, with the main portion of the wound cavity positioned over the wound). In each of these wound locations, and others, the anatomical location of the wound may present challenges to wound dressings with integrated squeeze pump assemblies due to the configuration of the anatomical structures, the mobility of the anatomical location, the radius of curvature at the anatomical location, or the location of the wound (which may not be easily visible or manually accessible to the patient). Notably, the NPWT bandage formed according to the invention has a wound cavity including a lateral extension, with the pump assembly in fluid communication with the lateral extension, such that the pump assembly is laterally offset from the wound while maintaining fluid communication with the wound. This allows the squeeze pump assembly to be positioned in an easily accessible, physically stable anatomical location while still maintaining air / fluid communication with the wound.

[0133] This novel NPWT bandage may include any number of geometric features, including but not limited to: 1- An oral cavity with lateral extensions of varying lengths (e.g., short, long, etc.), wherein the lateral extensions are aligned in line with the center of the dressing, and the squeeze pump assembly is oriented at any angle to the centerline of the dressing; and 2- The wound cavity has lateral extensions of different lengths (e.g., short, long, etc.), wherein the lateral extensions are positioned off-center from the centerline of the dressing.

[0134] As an example, not a limitation, Figures 39-42 An alternative structure for a negative pressure wound therapy (NPWT) bandage 5 is shown, wherein the lateral extension of the wound cavity has the same... Figures 35-38 The different lengths shown.

[0135] As a further example rather than a limitation, Figures 43-46 An alternative structure for a negative pressure wound therapy (NPWT) bandage 5 is shown, wherein the squeeze pump assembly extends transversely to the axis of the lateral extension of the wound cavity.

[0136] As a further example rather than a limitation, see now. Figure 46A The second portion 410 of the oral cavity may extend parallel to the first portion 405 of the oral cavity, but offset from the first portion 405 of the oral cavity (instead of being adjacent to one end of the first portion 405 of the oral cavity, such as...). Figures 35-38 (As shown in the structures of 39-42 and 43-46). Pump assembly 15 is mounted to the second part 410 for fluid communication with the wound cavity (to communicate with...). Figures 35-38(The structures of 39-42 and 43-46 are the same), however, in Figure 46A In the structure shown, the pump assembly 15 extends substantially parallel to the first portion 405 of the wound cavity. Note that, utilizing... Figure 46A The structure of the negative pressure wound therapy (NPWT) bandage 5, its footprint, is likely more like a "square" (in the sense that the length and width of the bandage are more equal) than a "long rectangle" (in the sense that the length of the bandage is much greater than the width of the bandage), such as... Figures 35-38 As shown in the structures 39-42 and 43-46.

[0137] If needed, Figure 17-20 The notch 105 formed in the pump body 60 of the pump assembly shown and / or in Figure 26-28 The notch 105 formed in the pump body 60 of the pump assembly shown can also be formed in Figures 35-38 , Figures 39-42 and Figures 43-46 The corresponding pump body of the NPWT bandage 5 shown. Additionally, if needed, the can 200 can be connected to... Figures 35-38 , Figures 39-42 and Figures 43-46 The pump assembly of the NPWT bandage 5 shown is used together. Furthermore, the Luer lock 300 can be used with, if desired. Figures 35-38 , Figures 39-42 and Figures 43-46 The NPWT bandage 5 shown is used in conjunction with the pump assembly.

[0138] A negative pressure wound therapy (NPWT) bandage for covering wounds, the bandage including a transparent top layer that will... The foam layer is trapped against the wound and is provided with a series of windows that (i) allow direct observation of the wound. (ii) Provide a metric along the length of the bandage to indicate whether the bandage needs to be replaced; additionally, the foam... The foam layer includes a peripheral serrated structure that allows the bandage to conform to the curved wound.

[0139] The foregoing description discloses various negative pressure wound therapy (NPWT) bandages that cover a wound and apply negative pressure to it to help prevent infection. The NPWT bandages disclosed in the foregoing description typically include (i) a membrane 10 for placement on the wound, and (ii) an integrated pump assembly 15 for applying and maintaining negative pressure at the wound site.

[0140] like Figure 21-46As shown in the structure, the membrane 10 typically includes (i) a lower polyurethane layer 110 for contacting the skin with an opening 115 disposed over a wound, (ii) an intermediate foam layer 120 disposed over the opening 115 in the lower polyurethane layer 110 for contacting the wound, and (iii) an upper polyurethane layer 125 disposed over the intermediate foam layer 120 and the lower polyurethane layer 110 for contacting the skin, wherein the outer peripheries of the upper polyurethane layer 125 and the lower polyurethane layer 110 for contacting the skin are fixed to each other, trapping the intermediate foam layer 120 therebetween, and further, the lower polyurethane layer 110 for contacting the skin is provided with an adhesive for adhering the membrane 10 to the patient's skin.

[0141] Pump assembly 15 can be centered above the wound (see...) Figure 1-25 The pump assembly 15 shown in the embodiment can be offset laterally from the wound (see...). Figures 35-46 The pump assembly 15 shown in the embodiment).

[0142] Because negative pressure is applied to the wound, exudate is often released from the wound site. In many cases, it may be desirable to obtain an indication of the amount of exudate produced by the wound, as high exudate production may require more frequent bandage changes (e.g., because the bandage may become saturated with exudate, or because exudate may reach the pump, which may impair pump function and / or cause exudate to be drained from the pump).

[0143] Therefore, a new bandage is now provided for wound types that easily release exudate. More specifically, see now. Figure 47 , 48 Figures 49 and 49 show a bandage 500 for application to wounds that are prone to exudation. The bandage 500 is similar to the NPWT bandage disclosed in the foregoing specification, except that the upper polyurethane layer 125 of the membrane 10 is replaced by an upper layer 505, and the intermediate foam layer 120 of the membrane 10 is replaced by a foam layer 510.

[0144] More specifically, the upper layer 505 of the bandage 500 is formed of 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 observe the foam layer 510 covering the wound (which absorbs exudate).

[0145] Foam layer 510 (see) Figures 47-55 A series of windows 515 extending through the foam layer are provided. These windows 515 allow direct observation of the wound and provide measurements along the length of the bandage to indicate whether it needs to be changed. Note that in Figure 50 In 53-55, for clarity, only the foam layer 510 of the bandage 500 is shown.

[0146] More specifically, see now Figure 51 and Figure 52 The transparent upper layer 505 allows the observer to view or observe whether a significant amount of exudate has migrated from the wound into the foam layer (exudate is typically pale yellow and therefore easily visible relative to the base color of the foam, which is preferably white, light gray, etc.), and the windows 515 provide a measurement extending along the length of the bandage (e.g., each window is a "marker line" along the bandage "ruler"). The amount of exudate draining from the wound is reflected by the amount (or extent) of foam showing the presence of exudate (this can be quantified by observing the portion of the foam layer 510 that displays the exudate and counting the number of windows adjacent to the area of ​​the foam layer 510 that displays the exudate). When the number of windows adjacent to the area of ​​the foam layer 510 that displays the exudate reaches a certain number along the length of the foam layer 510, the observer knows the amount of exudate leaving the wound and can decide whether to change the bandage. As an example and not a limitation, if the saturation of the foam layer 510 is less than 50% (e.g., Figure 51 As shown, which indicates that the number of windows adjacent to the area of ​​foam layer 510 displaying exudate 518 is three out of seven windows, a bandage can be left on the wound; however, if the saturation of foam layer 510 is greater than 50% (as shown in the diagram), the bandage can remain on the wound. Figure 52 As shown, if there are four or more windows adjacent to the area of ​​foam layer 510 displaying exudate 518, the bandage can be replaced. As a further example and not a limitation, when the area of ​​foam layer 510 surrounding the window closest to the pump shows the presence of exudate, it can be decided to replace the bandage to prevent exudate from reaching the pump.

[0147] In a preferred embodiment, the bandage 500 may be provided with markings 520 along its length. The markings 520 may be formed on the transparent upper layer 505 and / or the foam layer 510 (see [link]). Figures 50-55 As shown in Figures 53 and 54, mark 520 can be used in conjunction with window 515 in foam layer 510 to allow medical personnel to align bandage 500 along wound line 525 when applying bandage to wound.

[0148] If desired, the periphery of the foam layer 510 may be formed with a fan-shaped edge or a peripheral serrated structure 530 (see [reference]). Figures 47-55 ).like Figure 55As shown, the fan-shaped edge or peripheral serrated structure 530 allows the bandage 500 to be slightly bent when applied to the skin surface, thus enabling the bandage 500 to be positioned over a non-linear incision. Therefore, it is important to note that the portion of the bandage 500 positioned above the wound should not be bent excessively, as excessive bending can cause the bandage to wrinkle, potentially leading to a failure of the seal around the wound. The degree of bending that the bandage can withstand or accommodate without compromising its function depends on many factors, including but not limited to the size and geometry (width and depth) of the peripheral serrated structure 530 in the foam layer 510, the deformability of the upper layer 505, and the deformability of the lower polyurethane layer 110 in contact with the skin. If necessary, a peripheral serrated structure may also be formed in the upper layer 505 and / or the lower polyurethane layer 110 in contact with the skin to increase the degree of flexibility the bandage can accommodate (e.g., reducing the “wrinkling” of the upper layer 505 and the lower polyurethane layer 110 in contact with the skin when the bandage is positioned on a non-linear incision to increase the degree of flexibility the bandage can accommodate without compromising the airtight seal with the skin).

[0149] In one form of the invention, such as Figure 47 , 48 As shown in Figure 49, the bandage 500 is preferably a negative pressure wound therapy (NPWT) bandage with an integrated pump assembly 15, wherein the pump assembly 15 is laterally offset from the bandage 500 in this configuration, which is consistent with... Figures 35-37 The configuration of the NPWT bandages shown is essentially the same. However, if desired, the aforementioned transparent upper layer 505, window 515, marker 520, and peripheral serrated structure 530 can be provided together with other NPWT bandages having a laterally offset pump assembly, for example, such as Figures 39-42 The NPWT bandage and / or shown Figures 43-46 The NPWT bandage shown.

[0150] In another form of the invention, such as Figure 56 and 57 As shown, bandage 500 is a negative pressure wound therapy (NPWT) bandage with an integrated pump assembly 15, wherein the pump assembly 15 is positioned on a portion of the upper layer 505 and the foam layer 510.

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

[0152] This new type of bandage can also be used without applying negative pressure to the wound. This is intended as an example, not a limitation. Figure 58 and Figure 59As shown, the bandage 500 may omit the integrated pump and / or the connection to a pump located away from the bandage or to another suction source (e.g., a wall suction). In this form of the invention, the bandage 500 can essentially be used as a general-purpose bandage.

[0153] In other forms of the invention, the lower polyurethane layer 110 of the bandage 500 in contact with the skin 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. This is by way of example and not limitation. Figures 47-55 The structure can omit the lower polyurethane layer 110 that contacts the skin of the bandage 500, or Figure 56 and 57 The structure can omit the lower polyurethane layer 110 that contacts the skin of the bandage 500, or Figure 58 , 59 The structure of 60 can omit the lower polyurethane layer 110 that contacts the skin of the bandage 500.

[0154] In addition, it should be noted that the lower polyurethane layer 110 in contact with the skin can also be detached from... Figure 21-46 Omitted in any NPWT bandage shown, the upper polyurethane layer 125 is provided with (i) an adhesive for attaching the intermediate foam layer 120 to the upper polyurethane layer 125, and (ii) an adhesive for adhering the upper polyurethane layer 125 to the patient's skin.

[0155] If needed, Figure 17-20 The notch 105 formed in the pump body 60 of the pump assembly shown and / or in Figure 26-28 The notch 105 formed in the pump body 60 of the pump assembly shown can also be formed in Figures 47-49 The bandage 500 shown and in Figure 56 and 57 The bandage 500 shown is housed in the corresponding pump body. Additionally, if needed, the can 200 can be connected to... Figures 47-49 The bandage 500 shown and Figure 56 and 57 The bandage 500 shown is used with the pump assembly. Furthermore, if needed, the Luer lock 300 can be used with... Figures 47-49 The bandage 500 shown and Figure 56 and 57 The bandage 500 shown is used together with the pump assembly.

[0156] Removable film including peripheral frame It has been found that it is advantageous to provide an adhesive disposed on the lower polyurethane layer of the bandage in contact with the skin for the NPWT bandage of the present invention (e.g., the NPWT bandage 5, bandage 500, etc. described above), and together with this structure, to provide a removable film to cover the adhesive until the bandage is used.

[0157] Therefore, see now. Figure 61A This illustration shows a novel NPWT bandage 605 formed according to the present invention. The NPWT bandage 605 generally includes a membrane 610 for placement on a wound, and an integrated pump assembly 615 for applying and maintaining negative pressure at the wound site. Except as will be discussed in further detail below, the NPWT bandage 605 is generally similar to the NPWT bandage 5 discussed above.

[0158] More specifically, the membrane 610 generally comprises (i) a lower polyurethane layer 620 in contact with the skin having an opening 625 for being disposed over a wound, (ii) an intermediate foam layer 630 disposed over the opening 625 in the lower polyurethane layer 620 for contact with the wound, and (iii) an upper polyurethane layer 635 disposed over the intermediate foam layer 630 and the lower polyurethane layer 620 in contact with the skin, wherein the outer peripheries of the upper polyurethane layer 635 and the lower polyurethane layer 620 in contact with the skin are secured to each other, trapping the intermediate foam layer 630 therebetween, and further wherein the lower polyurethane layer 620 in contact with the skin is provided (e.g., coated) with an adhesive for adhering the membrane 610 to the patient's skin.

[0159] If desired, the lower polyurethane layer 620 in contact with the skin may include an adhesive covered by a removable film, as those skilled in the art will understand based on this disclosure. See now Figure 61B In one embodiment of the invention, a novel frame release (or peel-off) film 665 is provided, configured to facilitate easy aseptic application of an NPWT bandage 605 to a wound. More specifically, the frame release film 665 typically includes a removable central notched film portion 670, which is connected at one end to a removable peripheral frame film portion 680 via a coupling portion 675.

[0160] To apply the NPWT bandage 605, including the frame release film 665, to a wound, see now. Figures 62-69 The user holds the NPWT bandage 605 with the surface opposite to the surface including the frame release film 665 (e.g., the user holds the pump assembly 615 disposed on the upper polyurethane layer 635 of the film 610 with one hand). The user then grasps the end of the removable central release notch film portion 670 (at the end opposite to the coupling portion 675). Figure 62), and pull the removable center release notch film portion 670 away from the film 610, thereby exposing the center portion of the lower polyurethane layer 620 in contact with the skin (and thus, exposing any adhesive disposed on the lower polyurethane layer 620 in contact with the skin). Figure 63 ).

[0161] While holding the removable central notch film portion 670 (which is still connected to the removable peripheral frame film portion 680 via the connector 675) away from the NPWT bandage 605 with one hand and holding the pump assembly 615 with the other hand, the user centers the exposed central area of ​​the lower polyurethane layer 620 in contact with the skin over the wound to be treated. Figure 64 ), and the lower polyurethane layer 620 of the NPWT bandage 605 in contact with the skin is applied to the patient's anatomical structure ( Figure 65 ).

[0162] It is noteworthy that the outer periphery of the intermediate foam layer 630 is (i) larger than the periphery of the opening 625 of the lower polyurethane layer 620 in contact with the skin, and (ii) smaller than the outer periphery of both the lower polyurethane layer 620 and the upper polyurethane layer 635. In this way, (i) the adhesive disposed on the wound-side surface of the lower polyurethane layer 620 in contact with the skin seals the NPWT bandage 605 to the patient's skin, thereby forming a substantially airtight seal with the patient's skin around the periphery of the wound (i.e., for forming the aforementioned wound cavity), and (ii) fluid from the wound can pass through the opening 625 of the lower polyurethane layer 620 in contact with the skin to reach the intermediate foam layer 630.

[0163] The user then moves the removable central notch film portion 670 around the periphery of the NPWT bandage 605 to separate the removable peripheral frame film portion 680 from the lower polyurethane layer 620 in contact with the skin. Figures 66-68 ), until the removable peripheral frame film portion 680 is completely removed from the lower polyurethane layer 620 in contact with the skin ( Figure 69 Then the frame release film 665 is discarded. In this way, the frame release film 665 provides a one-piece or single-piece release liner that provides frame support for the wrinkle-free application of the NPWT bandage 605 to the patient's skin.

[0164] Alternative removable frame release film As discussed above, the aforementioned release film 665 includes a removable central notch film portion 670, which is connected at one end to a removable peripheral frame film portion 680 via a connector 675. Using the film 665, the user removes the film by pulling the central notch film portion 670 away from the film 610, and holds the central notch film portion 670 to one side when applying the NPWT bandage 605 to the patient's anatomy, with the exposed central area of ​​the lower polyurethane layer 620 in contact with the skin positioned substantially centrally over the wound to be treated. At this time, the connector 675 still connects the removable central notch film portion 670 to the removable peripheral frame film portion 680 (see...). Figure 64 and Figure 65 However, the connecting portion 675 is small and easily torn if too much force is applied to the membrane portion 670, making it difficult to apply the NPWT bandage to the patient's anatomy without wrinkling the membrane of the NPWT bandage.

[0165] In another form of the invention, see now. Figure 70 A novel frame release film 705 is shown, which solves the aforementioned problems of the frame release film 665 by providing a C-shaped notch between the connection between the central notch film portion and the peripheral frame film portion. This disperses the force applied to the connection portion during the removal of the frame release film, thereby reducing tearing between the central notch film portion and the peripheral frame film portion, as will be discussed in further detail below.

[0166] More specifically, see now Figures 70-74 The frame release film 705 typically includes a removable central notch film portion 710 and a removable peripheral frame film portion 715, the removable peripheral frame film portion being connected at one end to the central notch film portion 710 via a transition region 720.

[0167] The peripheral frame film portion 715 includes a notch adjacent to the transition region 720 (e.g., a generally C-shaped notch 725). Figure 73 and Figure 74The C-shaped notch 725 facilitates clean removal of the peripheral frame film portion from the skin-contacting lower polyurethane layer 620, while dispersing the force applied to the transition zone 720 (thus reducing the risk of tearing of the transition zone 720). The C-shaped notch 725 increases the spacing (i.e., gap) between the transition zone 720 and the removable peripheral frame film portion 715, and also facilitates removal of the removable peripheral frame film portion 715 from the skin-contacting lower polyurethane layer 620 by dispersing the force applied to the transition zone 720 to the removable peripheral frame film portion 715. More specifically, without the C-shaped notch 725, a highly concentrated force is directed onto the transition zone 720 when the frame release film 705 is removed from the skin-contacting lower polyurethane layer 620 of the NPWT bandage 605. By forming the C-shaped notch 725 in the peripheral frame film portion 715, the force is directed perpendicularly to the C-shaped notch 725, which disperses the force directed onto the transition zone 720.

[0168] The NPWT bandage 605, including the frame release film 705, is applied to the patient in a manner similar to that described above with respect to the NPWT bandage 605 including the frame release film 665. More specifically, when the user wishes to remove the frame release film 705 from the skin-contacting lower polyurethane layer 620 of the NPWT bandage 605, the user grasps the central notched film portion 710 (preferably at the end opposite to the C-shaped notch 725) and pulls the central notched film portion 710 away from the skin-contacting lower polyurethane layer 620, thereby exposing the central portion of the skin-contacting lower polyurethane layer 620 (and thus any adhesive applied to the skin-contacting lower polyurethane layer 620).

[0169] When the removable central notch film portion 710 is kept away from the NPWT bandage 605 (but still connected to the removable peripheral frame film portion 715 via the transition area 720), the user applies the skin-contacting lower polyurethane layer 620 of the NPWT bandage 605 to the patient's anatomy, while the exposed central area of ​​the skin-contacting lower polyurethane layer 620 is positioned approximately centered on the wound to be treated, and the adhesive on the wound-side surface of the skin-contacting lower polyurethane layer 620 seals the NPWT bandage 605 to the patient's skin, thereby forming a substantially airtight seal with the patient's skin around the periphery of the wound (i.e., for forming the aforementioned wound cavity).

[0170] Then, the user removes the removable peripheral frame film portion 715 from the lower polyurethane layer 620 that contacts the skin as follows: Figure 71The removable central notched film portion 710 is moved counterclockwise (i.e., towards the C-shaped notch 725, or clockwise from the user's perspective) around the periphery of the NPWT bandage 605 until the removable peripheral frame film portion 715 is completely removed from the underlying polyurethane layer 620 in contact with the skin. The frame release film 705 is then discarded. Thus, the frame release film 705 provides a one-piece or single-piece release liner that provides frame support for the wrinkle-free application of the NPWT bandage 605 to the patient's skin.

[0171] In yet another form of the invention, see now. Figures 75-77 This illustrates another novel frame release film 805. The novel frame release film 805 is generally similar to the frame release film 705 described above; however, for the novel frame release film 805, the C-shaped notch includes an inverted "hook" to make the outer circumferential portion of the frame release film more robust, as will be discussed in further detail below.

[0172] More specifically, see still Figures 75-77 The frame release film 805 typically includes a removable central notched film portion 810 and a removable peripheral frame film portion 815. The central notched film portion 810 is connected to the peripheral frame film portion 815 at one end via a transition region 820. The peripheral frame film portion 815 includes a notch adjacent to the transition region 820 (e.g., an inwardly extending C-shaped notch 825) that reduces the shear force acting on the transition region during removal of the peripheral frame film portion 815 from the underlying polyurethane layer in contact with the skin (thereby reducing the risk of tearing of the transition region 820).

[0173] It should be understood that the inwardly extending C-shaped notch 825 extends inside the innermost peripheral edge of the peripheral frame film portion 815 and outside the intermediate foam layer 630. Due to this structure, shear forces are minimized when the frame release film 805 is removed from the NPWT bandage 605, thereby ensuring that the transition zone 820 is less susceptible to tearing when the removable central notched film portion 810 and / or the removable peripheral frame film portion 815 separate from the lower polyurethane layer 620 in contact with the skin. To facilitate smooth separation of the peripheral frame film portion 815 and to ensure a fluid seal around the periphery of the wound cavity (i.e., the cavity defined by the opening 625 of the lower polyurethane layer 620 in contact with the skin), the C-shaped notch 825 preferably extends only inside the outermost edge of the lower polyurethane layer 620 in contact with the skin, thus not encroaching on the opening 625. In other words, the C-shaped notch 825 preferably does not extend into any part of the opening 625.

[0174] The NPWT bandage 605, including the frame release film 805, is applied to the patient in the same manner as described above regarding the NPWT bandage 605 including the frame release film 705, except that after applying the skin-contacting lower polyurethane layer 620 of the NPWT bandage 605 to the patient's anatomy, the removable peripheral frame film portion 815 is removed from the skin-contacting lower polyurethane layer 620 as follows: according to Figure 76 The reference frame is moved clockwise around the periphery of the NPWT bandage 605, with the removable central notch film portion 810 (i.e., toward the C-shaped notch 825, or clockwise from the perspective of the user applying the NPWT bandage) until the removable peripheral frame film portion 815 is completely removed from the underlying polyurethane layer 620 in contact with the skin. Thus, the frame release film 805 provides a one-piece or single-piece release liner that provides frame support for the wrinkle-free application of the NPWT bandage 605 to the patient's skin.

[0175] It should be understood that while frame release films 605 and 705 have been discussed in the context of the NPWT bandages (e.g., NPWT bandage 605) discussed above, frame release films 605, 705, and 805 can be placed on virtually any bandage used for performing negative pressure wound therapy on a patient. More generally, the present invention recognizes the benefits of providing a one-piece release liner that provides frame support for wrinkle-free application of NPWT bandages or other wound dressings. However, the present invention is not limited to use with the novel NPWT bandages disclosed herein; virtually any bandage / dressing for covering wounds can be modified to include the novel one-piece release liner of the present invention without departing from the scope of the invention.

[0176] Modifications to the preferred embodiment It should be understood that those skilled in the art can make many other changes to the details, materials, steps, and arrangements of parts described and shown herein for the purpose of explaining the nature of the invention, while still remaining within the principles and scope of the invention.

Claims

1. A removable film for covering an adhesive applied to the wound-side surface of a bandage, the removable film comprising: Central film portion; A peripheral film portion extending around the central film portion; as well as A transition zone that connects the peripheral film portion to the central film portion.

2. The removable film of claim 1, wherein the peripheral film portion includes a first end and a second end, and further wherein a notch is provided at the first end of the peripheral film portion, and the transition region is provided at the second end of the peripheral film portion.

3. The removable film of claim 2, wherein the notch in the peripheral film portion comprises a C-shaped notch.

4. The removable film of claim 3, wherein the C-shaped notch opens toward the central film portion.

5. The removable film of claim 3, wherein the C-shaped notch is opposite to the opening of the central film portion.

6. The removable film of claim 1, wherein the removable film includes a cut portion between the peripheral film portion and the central film portion.

7. The removable film of claim 1, wherein the bandage comprises a membrane configured to be applied to a wound to form an oral cavity between the membrane and the wound, the membrane comprising a wound-side surface and an atmospheric-side surface of the bandage, wherein an opening is formed in the wound-side surface, and further wherein the central film portion of the removable film is configured to extend over the opening.

8. The removable film of claim 7, wherein the film includes an outermost peripheral edge extending around the opening, and further wherein the peripheral film portion extends along the outermost peripheral edge of the film.

9. A method for removing a removable film from an adhesive disposed on a wound-side surface of a bandage, the removable film comprising a central film portion, a peripheral film portion extending around the central film portion, and a transition region connecting the peripheral film portion to the central film portion, the method comprising: Pull the central film portion toward the transition zone to expose the adhesive on the wound-side surface of the bandage; Position the wound-side surface of the bandage on the wound, while the central film portion remains connected to the peripheral film portion at the transition zone; as well as Move the central film portion around the bandage to pull the peripheral film portion away from the bandage, thereby removing the peripheral film portion and the central film portion from the bandage.

10. The method of claim 9, wherein the peripheral film portion includes a first end and a second end, and further wherein a notch is provided at the first end of the peripheral film portion, and the transition region is provided at the second end of the peripheral film portion.

11. The method of claim 10, wherein the notch in the peripheral film portion comprises a C-shaped notch.

12. The method of claim 11, wherein the C-shaped notch opens toward the central film portion, and the central film portion is moved clockwise around the bandage.

13. The method of claim 11, wherein the C-shaped notch is opposite to the opening of the central film portion, and the central film portion is moved counterclockwise around the bandage.

14. A negative pressure wound therapy (NPWT) bandage for applying negative pressure to a wound, said NPWT bandage comprising: A membrane configured to be applied to a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface and an atmospheric-side surface, wherein the wound-side surface includes an adhesive for adhering the membrane around the wound, and further wherein an opening is formed in the wound-side surface; A negative pressure source, fluidly connected to the opening in the membrane, for applying negative pressure to the wound cavity; as well as A removable film of adhesive covering the wound-side surface of the membrane, the removable film comprising: Central film portion; A peripheral film portion extending around the central film portion; and A transition zone that connects the peripheral film portion to the central film portion.

15. The NPWT bandage of claim 14, wherein the peripheral film portion includes a first end and a second end, and further wherein a notch is provided at the first end of the peripheral film portion, and the transition region is provided at the second end of the peripheral film portion.

16. The NPWT bandage of claim 15, wherein the notch in the peripheral film portion comprises a C-shaped notch.

17. The NPWT bandage of claim 16, wherein the C-shaped notch opens toward the central film portion.

18. The NPWT bandage of claim 16, wherein the C-shaped notch is opposite to the opening of the central film portion.

19. The NPWT bandage of claim 14, wherein the removal film includes a cut portion between the peripheral film portion and the central film portion.

20. The NPWT bandage of claim 14, wherein the central film portion of the removable film is configured to extend over the opening in the film.

21. The NPWT bandage of claim 20, wherein the membrane includes an outermost peripheral edge extending around the opening, and further wherein the peripheral film portion extends along the outermost peripheral edge of the membrane.

22. The NPWT bandage of claim 14, wherein the central film portion is configured to extend over the opening in the membrane and over at least a portion of the membrane surrounding the periphery of the opening, wherein the peripheral film portion is configured to extend around the periphery of the central film portion to cover an area of ​​the wound-side surface of the membrane not covered by the central film portion.

23. The NPWT bandage of claim 22, wherein the peripheral film portion includes a first end and a second end, wherein a notch is provided at the first end of the peripheral film portion, and the transition region is provided at the second end of the peripheral film portion, and further, wherein the notch does not extend into the central film portion of the removable film.

24. A method for applying negative pressure to a wound, the method comprising: Provides negative pressure wound therapy (NPWT) bandages, which include: A membrane configured to be placed on a wound to form a wound cavity between the membrane and the wound, the membrane including a wound-side surface and an atmospheric-side surface, wherein the wound-side surface includes an adhesive, and further wherein an opening is formed in the wound-side surface; A negative pressure source, fluidly connected to the opening in the membrane, is used to apply negative pressure to the wound cavity; and A removable film of adhesive covering the wound-side surface of the membrane, the removable film comprising: Central film portion; Peripheral film portion and A transition region that connects the peripheral film portion to the central film portion; Pull the central film portion toward the transition zone to expose the adhesive on the wound-side surface of the bandage; Position the wound-side surface of the bandage above the wound, while the central film portion remains connected to the peripheral film portion at the transition zone; The central film portion is moved around the membrane to pull the peripheral film portion away from the membrane, thereby removing the peripheral film portion and the central film portion from the membrane; and The pump assembly is used to generate negative pressure in the wound cavity.

25. The method of claim 24, wherein the peripheral film portion includes a first end and a second end, and further wherein a notch is provided at the first end of the peripheral film portion, and the transition region is provided at the second end of the peripheral film portion.

26. The method of claim 25, wherein the notch in the peripheral film portion comprises a C-shaped notch.

27. The method of claim 26, wherein the C-shaped notch opens toward the central film portion, and the central film portion is moved clockwise around the bandage.

28. The method of claim 26, wherein the C-shaped notch is opposite to the opening of the central film portion, and the central film portion is moved counterclockwise around the bandage.

Images