Fluid connector for negative pressure wound therapy

Abstract

Disclosed herein is a negative pressure device and method of operating the same in treating wounds with negative pressure, and an improved fluid connector or suction adapter for connecting a negative pressure source to a wound, having an air leak channel separate from the suction channel.

Description

[Technical field]

[0001]

[0002] Embodiments of the present disclosure relate to methods and apparatus for covering and treating wounds using reduced pressure, or topical negative pressure (TNP) therapy. In particular, but not limited to, embodiments disclosed herein relate to negative pressure therapy devices, methods for controlling the operation of TNP systems, and methods of using TNP systems.

[0002] 2. Description of Related Art Many different types of wound dressings are known to aid in human or animal healing procedures. These different types of wound dressings include different types of materials and layers, such as gauze, pads, foam pads, or multi-layer wound dressings. Topical negative pressure (TNP) therapy, sometimes referred to as vacuum-assisted closure therapy, negative pressure wound therapy (NPWT), or reduced pressure wound therapy, is widely recognized as a beneficial mechanism for improving wound healing rates. Such therapy is applicable to a wide range of wounds, such as surgical wounds, open wounds, and abdominal wounds.

[0003] TNP treatment may promote wound closure and healing by reducing tissue edema, increasing blood flow, promoting the formation of granulation tissue, and removing excess exudate, and may reduce bacterial load and infection in the wound. Additionally, TNP treatment allows for less external trauma to the wound and promotes more rapid healing. Summary of the Invention

[0004] SUMMARY OF THE DISCLOSURE The embodiments disclosed herein are directed to apparatus, systems, devices and methods for use in negative pressure wound therapy.

[0005] The fluid connector for negative pressure wound treatment may include a top layer, a bottom layer, and a middle layer. Each layer may be constructed from a flexible liquid impermeable material. Each layer may include a proximal end and a distal end. The connector may include an upper fluid passage at least partially defined between the top layer and the middle layer. The upper fluid passage may include a proximal end and a distal end. The upper fluid passage may include an upper channel spacer material positioned between the top layer and the middle layer. The upper fluid passage may be configured to provide gas from an opening in the top layer located at or near a proximal end of the upper fluid passage. The connector may include a lower fluid passage at least partially defined between the middle layer and the bottom layer. The lower fluid passage may be configured to be in fluid communication with a negative pressure source. The lower fluid passage may include a lower channel spacer material positioned between the middle layer and the bottom layer. The connector may include an opening at a distal end of the bottom layer. The opening in the bottom layer may be configured to be positioned over an opening in a dressing configured to be positioned over a wound. The opening in the bottom layer can be fluidly connected to the lower fluid passage. The connector can include an opening at a distal end of the middle layer. The opening in the middle layer can be fluidly connected to the upper fluid passage. The opening in the middle layer can be positioned over the opening in the bottom layer. The distal end of the upper channel spacer material can extend further distally than the distal end of the lower channel spacer material. The lower fluid passage can include a portion at the distal end that is free of the lower channel spacer material. The portion of the lower fluid passage can include an opening in the bottom layer. When negative pressure is applied to the lower fluid passage from a negative pressure source, the portion of the lower fluid passage can collapse, blocking fluid flow between the lower and upper channel spacer materials through the portion of the lower fluid passage but allowing fluid flow between the lower and upper channel spacer materials through the opening in the dressing, the opening in the bottom layer, and the opening in the middle layer.

[0006] The fluid connector of any of the preceding paragraphs and / or any of the fluid connectors disclosed herein may include one or more of the following features: A portion of the lower channel spacer material at the distal end may overlap the opening in the bottom layer. The fluid connector may include an applicator attached to the bottom layer at the distal end, the applicator including an adhesive configured to be adhered to the dressing. The applicator may include an opening disposed immediately below the opening in the bottom layer and configured to be positioned above the opening in the dressing. At least a portion of the opening in the middle layer may overlap the opening in the applicator. The opening in the bottom layer may be wider than the opening in the middle layer. The center of the opening in the middle layer may be positioned further distal than the center of the opening in the bottom layer. The upper channel spacer material may include a foam. The lower channel spacer material may be a 3D knit or 3D fabric material. Each of the top and bottom layers may have an extended distal end. The extended ends of the top and bottom layers may be rectangular or may form a teardrop shape. The bottom layer is configured to be attached to the dressing. The opening in the top layer can include a filter. The fluid connector can include a connector in fluid communication with a proximal end of the lower channel spacer material, the connector configured to be fluidly connected to a negative pressure source.

[0007] The fluid connector for negative pressure wound therapy may include an upper fluid passage. The upper fluid passage may be configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage. The fluid connector may include a lower fluid passage. The lower fluid passage may be configured to be in fluid communication with a negative pressure source and to allow fluid to flow through the lower fluid passage toward the negative pressure source. The fluid connector may include an intermediate layer between the upper and lower fluid passages. The intermediate layer may include a fluid impermeable material. The fluid connector may include a first opening at a distal end of the lower fluid passage. The first opening may be configured to be positioned over an opening in a dressing configured to be positioned over a wound. The fluid connector may include a second opening at a distal end of the intermediate layer, a second opening positioned over the first opening in the bottom layer, and a second opening fluidly connected to the upper fluid passage. The upper fluid passage may extend further distally than the lower fluid passage, and the lower fluid passage may include an void in which the first opening is located. When negative pressure is applied to the lower fluid passage from a negative pressure source, the void collapses blocking fluid flow between the upper and lower fluid passages through the void but allowing fluid flow between the upper and lower fluid passages through the dressing and filler positioned in the wound.

[0008] The fluid connector of any of the preceding paragraphs and / or any of the fluid connectors disclosed herein may include one or more of the following features: The lower fluid passage may include a material. A portion of the material at a distal end of the lower fluid passage may overlap with the first opening. The fluid connector may include an applicator attached to a bottom surface of the fluid connector at a distal end. The applicator may include an adhesive configured to be adhered to the dressing. The applicator may include an opening immediately below the first opening. The applicator may be configured to be positioned over an opening in the dressing. At least a portion of the second opening may overlap with an opening in the applicator. The first opening may be wider than the second opening. The center of the second opening may be positioned further distally from the center of the first opening. The gas may include air.

[0009] A method of operating any of the fluid connectors of the preceding paragraphs and / or any of the fluid connectors described herein is disclosed. A method of operating a negative pressure wound treatment system is disclosed, including any of the fluid connectors of the preceding paragraphs and / or any of the fluid connectors described herein. The method of operating a negative pressure wound treatment system may include providing a suction adapter. The suction adapter may include an upper fluid passage configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage. The suction adapter may include a lower fluid passage configured to fluidly communicate with a negative pressure source and to allow fluid to flow through the lower fluid passage toward the negative pressure source. The suction adapter may include an intermediate layer between the upper fluid passage and the lower fluid passage. The intermediate layer may include a fluid impermeable material. The suction adapter may include a first opening at a distal end of the lower fluid passage. The first opening may be configured to be positioned over an opening in a dressing configured to be positioned over a wound. The suction adapter may include a second opening at a distal end of the intermediate layer. The second opening may be located above the first opening in the bottom layer. The second opening may be fluidly connected to the upper fluid passage. The upper fluid passage may extend further distally than the lower fluid passage. The lower fluid passage may include an open area in which the first opening is located. The method may include applying negative pressure from a negative pressure source to the wound through the lower fluid passage of the suction adapter, collapsing the open area and blocking fluid flow between the upper and lower fluid passages through the open area, but allowing at least some gas from the upper fluid passage to flow through the dressing and wound filler positioned within the wound, and allowing gas to be aspirated through the lower fluid passage when the suction adapter is attached to the dressing and the first opening is positioned in fluid communication with the opening in the dressing.

[0010] The fluid connector for negative pressure wound treatment may include a top layer, a bottom layer, and a middle layer. Each layer may be constructed from a flexible liquid impermeable material. Each layer may include a proximal end and a distal end. The connector may include an upper fluid passage at least partially defined between the top layer and the middle layer. The upper fluid passage may include a proximal end and a distal end. The upper fluid passage may include an upper channel spacer material positioned between the top layer and the middle layer. The upper fluid passage may be configured to provide gas from an opening in the top layer located at or near a proximal end of the upper fluid passage. The connector may include a lower fluid passage at least partially defined between the middle layer and the bottom layer. The lower fluid passage may be configured to be in fluid communication with a negative pressure source. The lower fluid passage may include a lower channel spacer material positioned between the middle layer and the bottom layer. The connector may include one or more openings at a distal end of the bottom layer. The one or more openings in the bottom layer may be configured to be positioned over an opening in the dressing configured to be positioned over the wound. At least one of the one or more openings in the bottom layer may be fluidly connected to the lower fluid passage. The connector may include an opening at a distal end of the middle layer. The opening in the middle layer may be fluidly connected to the upper fluid passage. The opening in the middle layer may be positioned over at least one of the one or more openings in the bottom layer. The distal end of the upper channel spacer material may extend further distally than at least a portion of the distal end of the lower channel spacer material, such that the lower fluid passage can include a portion at the distal end free of the lower channel spacer material. The portion of the lower fluid passage may include one or more openings in the bottom layer.

[0011] The fluid connector of any of the preceding paragraphs and / or any of the fluid connectors disclosed herein may include one or more of the following features: When negative pressure is applied to the lower fluid passage from a negative pressure source, a portion of the lower fluid passage may collapse, blocking fluid flow between the lower channel spacer material and the upper channel spacer material through the portion of the lower fluid passage, but allowing fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the dressing, the one or more openings in the bottom layer, and the opening in the middle layer. The portion of the lower channel spacer material at the distal end may overlap one of the one or more openings in the bottom layer. The fluid connector may include an applicator attached to the bottom layer at the distal end, the applicator including an adhesive configured to be adhered to the dressing. The applicator may include an opening disposed immediately below the one or more openings in the bottom layer and configured to be positioned above the opening in the dressing. At least a portion of the opening in the middle layer may overlap an opening in the applicator. The one or more openings in the bottom layer may be wider than the opening in the middle layer. The center of the opening in the middle layer may be located further distal than the center of each of the one or more openings in the bottom layer. The upper channel spacer material may include a foam. The lower channel spacer material may be a 3D knit or 3D fabric material. Each of the top and bottom layers may have an extended distal end. The extended ends of the top and bottom layers may be rectangular or may form a teardrop shape. The bottom layer is configured to be attached to a dressing. The opening in the top layer may include a filter. The fluid connector may include a connector in fluid communication with a proximal end of the lower channel spacer material, the connector configured to be fluidly connected to a negative pressure source. The lower fluid passage may include a welded portion, where a portion of the bottom layer may be welded to the middle layer.When negative pressure is applied to the lower fluid passage from a negative pressure source, the welded portion of the lower fluid passage can block fluid flow between the lower channel spacer material and the upper channel spacer material through the portion of the lower fluid passage, but allow fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the cladding, the one or more openings in the bottom layer, and the opening in the middle layer. The portion of the lower fluid passage can include a distal portion and a proximal portion separated from a distal portion by the welded portion of the lower fluid passage. The one or more openings in the bottom layer can include two openings. The welded portion of the bottom layer can be located between the two openings. The shape of at least one of the two openings can be semicircular. The distal end of the lower channel spacer material can include a fork shape including a base portion between two side portions. The two side portions can extend distally from the base portion, the one or more openings in the bottom layer, and the opening in the middle layer. The base portion can be proximal to the one or more openings in the bottom layer and the opening in the middle layer. The lower fluid passageway may be positioned between the two side portions of the lower channel spacer material and distal to the base portion of the lower channel spacer material.

[0012] The fluid connector for negative pressure wound therapy may include an upper fluid passage. The upper fluid passage may be configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage. The fluid connector may include a lower fluid passage. The lower fluid passage may be configured to be in fluid communication with a negative pressure source and to allow fluid to flow through the lower fluid passage toward the negative pressure source. The fluid connector may include an intermediate layer between the upper and lower fluid passages. The intermediate layer may include a fluid impermeable material. The fluid connector may include one or more first openings at a distal end of the lower fluid passage. The one or more first openings may be configured to be positioned over an opening in a dressing configured to be positioned over a wound. The fluid connector may include a second opening at a distal end of the intermediate layer. The second opening may be positioned over at least one of the one or more first openings in the bottom layer. The second opening may be fluidly connected to the upper fluid passage. The upper fluid passage may extend further distally than the lower fluid passage, and the lower fluid passage may include an open portion in which the one or more first openings are located. When negative pressure is applied to the lower fluid passage from a negative pressure source, fluid flow may be blocked between the upper and lower fluid passages through the open portion but allows fluid flow between the upper and lower fluid passages through the dressing and filler positioned within the wound.

[0013] The fluid connector of any of the preceding paragraphs and / or any of the fluid connectors disclosed herein may include one or more of the following features: The open portion collapses in response to a negative pressure applied to the lower fluid passage such that fluid flow can be blocked between the upper and lower fluid passages through the open portion. The open portion may include a welded portion, where a portion of the bottom layer may be welded to the middle layer. The welded portion may be adapted to block fluid flow between the upper and lower fluid passages through the open portion when negative pressure is applied to the lower fluid passage. The open portion of the lower fluid passage may include a distal portion and a proximal portion separated from the distal portion by a welded portion of the lower fluid passage. The one or more openings of the bottom layer may include two openings. The welded portion of the bottom layer may be located between the two openings. The shape of at least one of the two openings may be semicircular. The lower fluid passage may include a lower channel spacer material. A portion of the lower channel spacer material at a distal end of the lower fluid passage may overlap one of the one or more first openings. A portion of the lower channel spacer material at a distal end of the lower fluid passage may abut a distal edge of one of the one or more first openings. The portion of the lower channel spacer material at a distal end of the lower fluid passage may include a fork shape including a base portion between two side portions. The two side portions may extend distally from the base portion, the one or more first openings in the bottom layer, and the opening in the middle layer. The base portion may be proximal to the one or more first openings in the bottom layer and the opening in the middle layer. The portion of the lower fluid passage may be positioned between the two side portions of the lower channel spacer material and distal to the base portion of the lower channel spacer material. The fluid connector may include an applicator attached to a bottom surface of the fluid connector at a distal end. The applicator may include an adhesive configured to be adhered to the dressing. The applicator may include an opening immediately below the one or more first openings. The applicator may be configured to be positioned over an opening in the dressing. At least a portion of the second opening may overlap an opening in the applicator. One or more of the first openings may be wider than the second openings.The center of the second opening may be located further distally from the center of each of the first one or more openings. The gas may include air.

[0014] A method of operating a negative pressure wound therapy system may include providing a suction adapter. The suction adapter may include an upper fluid passage configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage. The suction adapter may include a lower fluid passage configured to fluidly communicate with a negative pressure source and allow fluid to flow through the lower fluid passage toward the negative pressure source. The suction adapter may include an intermediate layer between the upper and lower fluid passages. The intermediate layer may include a fluid impermeable material. The suction adapter may include one or more first openings at a distal end of the lower fluid passage. The one or more first openings may be configured to be positioned over an opening in a dressing configured to be positioned over a wound. The suction adapter may include a second opening at a distal end of the intermediate layer. The second opening may be positioned over at least one of the one or more first openings in the bottom layer. The second opening may be fluidly connected to the upper fluid passage. The upper fluid passage may extend further distally than the lower fluid passage. The lower fluid passage may include an open portion in which the one or more first openings are located. The method may include applying negative pressure from a negative pressure source to the wound through the lower fluid passage of the suction adapter, causing the open portion to block fluid flow between the upper and lower fluid passages through the open portion, but allowing at least some gas from the upper fluid passage to flow through a dressing and wound filler positioned in the wound, and further allowing gas to be aspirated through the lower fluid passage when the suction adapter is attached to the dressing and the one or more first openings are positioned in fluid communication with openings in the dressing.

[0015] The method of any of the preceding paragraphs and / or any of the methods disclosed herein may include one or more of the following features: Applying negative pressure from a negative pressure source to the wound through a lower fluid passage of the suction adaptor may collapse the open portion, thereby selectively blocking fluid flow. The open portion may include a welded portion where the bottom layer may be welded to the middle layer, whereby the welded portion selectively blocks fluid flow while negative pressure from a negative pressure source is applied to the wound through the lower fluid passage of the suction adaptor.

[0016] Other embodiments of the apparatus for use with negative pressure, devices and associated methods are described below. [Brief description of the drawings]

[0017] [Figure 1] 1 illustrates a reduced pressure wound treatment system according to some embodiments. [Diagram 2] 1 illustrates a pump assembly and a canister according to some embodiments. [Diagram 3] 1 illustrates an electrical component schematic of a pump assembly according to some embodiments. [Figure 4A] 1 illustrates an embodiment of a negative pressure wound treatment system including a pump and showing a flexible suction adapter being applied to a wound. [Figure 4B] 4B illustrates the embodiment of FIG. 4A with a flexible suction adapter positioned over the wound. [Figure 5A] 1 illustrates an isometric view of a flexible suction adapter that may be used in a negative pressure wound treatment system. [Figure 5B] 5B illustrates an exploded view of the flexible suction adapter of FIG. 5A. [Figure 5C] 5C illustrates a close-up view of the proximal end of the flexible suction adapter of FIG. 5B. [Figure 5D] 2B illustrates an enlarged cutaway view of the proximal end of the flexible suction adapter of FIG. 2A. [Figure 5E] 5B illustrates a top view of the flexible suction adapter of FIG. 5A. [Figure 5F] 5B illustrates a side view of the flexible suction adapter of FIG. 5A. [Figure 5G] 5B illustrates a bottom view of the flexible suction adapter of FIG. 5A. [Figure 6] 1 illustrates an exploded view of an alternative flexible suction adapter. [Figure 7A] 1 illustrates a top view of a 3D fabric that may be used in a negative pressure wound treatment device. [Figure 7B] FIG. 7B illustrates a bottom view of the 3D fabric of FIG. [Figure 7C] 7B illustrates a side cutaway view of the 3D fabric of FIG. 7A. [Figure 8A] 5B illustrates one embodiment of a connector having two or more protrusions that can be connected to the suction adapter illustrated in FIG. 5A. [Figure 8B] 5B illustrates one embodiment of a connector having two or more protrusions that can be connected to the suction adapter illustrated in FIG. 5A. [Figure 9A] 1 illustrates an exploded view of a flexible suction adapter that may be used in a negative pressure wound treatment system. [Figure 9B] 9B illustrates a top view of the flexible suction adapter of FIG. 9A. [Figure 9C] 9B illustrates a cross-sectional view of the flexible suction adapter of FIG. 9A. [Figure 10] 1 illustrates a diagram of a system for applying negative pressure according to some embodiments. [Figure 11A] 1 illustrates a negative pressure wound treatment system including a negative pressure device, illustrating a pair of flexible suction adapters applied to a wound, according to some embodiments. [Figure 11B] 11B illustrates one embodiment of FIG. 11A with a flexible suction adapter positioned over the wound. [Figure 12] 1 illustrates a diagram of a system for applying negative pressure according to some embodiments. [Figure 13] 1 illustrates a flow diagram of a process for determining and indicating one or more operating conditions, according to some embodiments. [Figure 14] 1 illustrates a flow diagram of a process for determining and indicating one or more operating conditions, according to some embodiments. [Figure 15]1 illustrates a cross-sectional view of a flexible suction adapter that may be used in a negative pressure wound treatment system. [Figure 16] 16 illustrates an exploded view of a portion of the flexible suction adapter of FIG. 15. [Figure 17] 16 illustrates an exploded view of a portion of the flexible suction adapter of FIG. 15. [Figure 18] 16 illustrates a bottom view of the flexible suction adapter of FIG. 15. [Figure 19] 16 illustrates the flexible suction adapter of FIG. 15 attached to a wound dressing and subjected to negative pressure. [Figure 20] 16 illustrates the flexible suction adapter of FIG. 15 attached to a wound dressing and subjected to negative pressure. [Figure 21] 16 illustrates the flexible suction adapter of FIG. 15 attached to a wound dressing and subjected to negative pressure. [Figure 22] 14A-14C illustrate bottom views of different embodiments of a flexible suction adapter. [Diagram 23] 14A-14C illustrate bottom views of different embodiments of a flexible suction adapter. [Figure 24A] 24A and 24B illustrate bottom views of one embodiment of the middle layer (FIG. 24A) and bottom layer (FIG. 24B) of a flexible suction adapter. [Figure 24B] 24A and 24B illustrate bottom views of one embodiment of the middle layer (FIG. 24A) and bottom layer (FIG. 24B) of a flexible suction adapter. [Figure 25A] 25A and 25B illustrate bottom views of one embodiment of the middle layer (FIG. 25A) and bottom layer (FIG. 25B) of a flexible suction adapter. [Figure 25B] 25A and 25B illustrate bottom views of one embodiment of the middle layer (FIG. 25A) and bottom layer (FIG. 25B) of a flexible suction adapter. [Figure 26A] 26A and 26B illustrate bottom views of one embodiment of the middle layer (FIG. 26A) and bottom layer (FIG. 26B) of a flexible suction adapter. [Figure 26B] 26A and 26B illustrate bottom views of one embodiment of the middle layer (FIG. 26A) and bottom layer (FIG. 26B) of a flexible suction adapter. [Figure 27]1 illustrates a cross-sectional view of one embodiment of a flexible suction adapter that may be used in a negative pressure wound treatment system. [Figure 28A] 28A and 28B illustrate bottom views of one embodiment of the middle layer (FIG. 28A) and bottom layer (FIG. 28B) of a flexible suction adapter. [Figure 28B] 28A and 28B illustrate bottom views of one embodiment of the middle layer (FIG. 28A) and bottom layer (FIG. 28B) of a flexible suction adapter. [Figure 29A] 29A and 29B illustrate bottom views of one embodiment of the middle layer (FIG. 29A) and bottom layer (FIG. 29B) of a flexible suction adapter. [Figure 29B] 29A and 29B illustrate bottom views of one embodiment of the middle layer (FIG. 29A) and bottom layer (FIG. 29B) of a flexible suction adapter. [Figure 30A] 30A and 30B illustrate bottom views of one embodiment of the middle layer (FIG. 30A) and bottom layer (FIG. 30B) of a flexible suction adapter. [Figure 30B] 30A and 30B illustrate bottom views of one embodiment of the middle layer (FIG. 30A) and bottom layer (FIG. 30B) of a flexible suction adapter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] overview The embodiments disclosed herein relate to apparatus, systems, devices and methods for treating wounds with reduced pressure. As used herein, a reduced pressure or negative pressure level, such as -XmmHg, refers to a pressure level relative to normal ambient air pressure, which may correspond to 760mmHg (or 1 atm, 29.93 inHg, 101.325 kPa, 14.696 psi, etc.). Thus, a negative pressure value of -XmmHg reflects an absolute pressure of XmmHg less than 760mmHg, or in other words, an absolute pressure of (760-X)mmHg. Furthermore, a negative pressure "lower" or "smaller" than XmmHg corresponds to a pressure closer to atmospheric pressure (e.g., -40mmHg is lower than -60mmHg). A negative pressure "higher" or "larger" than -XmmHg corresponds to a pressure further from atmospheric pressure (e.g., -80mmHg is higher than -60mmHg). In some embodiments, the local ambient air pressure is used as a reference point, and such local air pressure need not necessarily be, for example, 760 mmHg.

[0019] The embodiments of the present disclosure are generally applicable for use in topical negative pressure (TNP) or reduced pressure treatment systems. In brief, negative pressure wound treatment can assist in the closure and healing of many forms of "hard to heal" wounds by reducing tissue edema, encouraging blood flow and granular tissue formation, and removing excessive exudate, reducing bacterial load (and therefore infection risk). In addition, treatment can reduce wound unrest, leading to faster healing. TNP treatment systems can also assist in the healing of surgically closed wounds by removing fluids. In some embodiments, TNP treatment helps stabilize tissues in opposition to closure. Further beneficial uses of TNP treatment can be found in grafts and flaps, where removing excess fluid is important and grafts are required to be in close proximity to tissue to ensure tissue viability.

[0020] Negative Pressure System FIG. 1 illustrates an embodiment of a negative pressure or reduced pressure wound therapy (or TNP) system 100 including a wound cavity 110 and a wound filler 130 disposed within the wound cavity sealed by a wound cover 120. The wound filler 130 in combination with the wound cover 120 may be referred to as a wound dressing. A flow path 140, such as a single or multiple lumen tube or conduit, connects the wound cover 120 to a negative pressure wound therapy device, e.g., a pump assembly 150, configured to provide reduced pressure. The wound cover 120 may be in fluid communication with the wound cavity 110. In some system embodiments disclosed herein, such as the embodiment shown in FIG. 1, the pump assembly may be a canisterless pump assembly (meaning that exudate is collected in the wound dressing or conveyed via the tube 140 for collection at another location). However, some pump assembly embodiments disclosed herein may be configured to include or support a canister. Additionally, in some system embodiments disclosed herein, some pump assembly embodiments may be attached to or supported by the dressing or adjacent to the dressing. The wound filler 130 may be of any suitable type, such as hydrophilic or hydrophobic foam, gauze, inflatable bag, etc. The wound filler 130 may conform to the wound cavity 110 such that it substantially fills the cavity. The wound cover 120 may provide a substantially fluid-impermeable seal over the wound cavity 110. The wound cover 120 may have a top surface and a bottom surface, the bottom surface adhesively (or in any other suitable manner) seals the wound cavity 110. The conduit 140 or lumen or any other conduit or lumen disclosed herein may be formed from polyurethane, PVC, nylon, polyethylene, silicone, or any other suitable material.

[0021] Some embodiments of the wound cover 120 may have a port (not shown) configured to receive an end of the conduit 140. In other embodiments, the conduit 140 may otherwise pass through or under the wound cover 120 to provide reduced pressure to the wound cavity 110 to maintain a desired level of reduced pressure within the wound cavity. The conduit 140 may be any suitable article configured to provide at least a substantially sealed fluid flow path between the pump assembly 150 and the wound cover 120 to provide reduced pressure provided by the pump assembly 150 to the wound cavity 110. The wound cover 120 and the wound filler 130 may be provided as a single article or an integral single unit. In some embodiments, no wound filler may be provided and the wound cover may be considered a wound dressing in itself. The wound dressing may then be connected to a negative pressure source, such as the pump assembly 150, via the conduit 140. The pump assembly 150 may be miniaturized and portable, although larger conventional such pumps may also be used.

[0022] The wound cover 120 may be positioned over the wound site to be treated. The wound cover 120 may form a substantially sealed cavity or enclosed space over the wound site. In some embodiments, the wound cover 120 may be configured to have a film with high water vapor permeability to allow evaporation of excess fluids and may have a superabsorbent material included therein to safely absorb wound exudate. It will be understood that wounds are referred to throughout this specification. In this regard, it should be understood that the term wound is broadly construed to include open and closed wounds where the skin is torn, cut, or perforated, or where trauma has caused a bruise, or any other surface or other condition or defect in the skin of a patient, or person who would benefit from reduced pressure treatment. Thus, a wound is broadly defined as any damaged area of ​​tissue where fluid may or may not be produced. Examples of such wounds include, but are not limited to, acute wounds, chronic wounds, surgical incisions and other incisions, subacute and dehiscence wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, diabetic ulcers, pressure ulcers, stomas, surgical wounds, traumatic ulcers and venous ulcers, etc. Components of the TNP system described herein may be particularly suitable for surgical wounds that exude small amounts of wound exudate.

[0023] Some embodiments of the system are designed to operate without the use of an exudate canister. Some embodiments may be configured to support an exudate canister. In some embodiments, configuring the pump assembly 150 and tubing 140 so that the tubing 140 can be quickly and easily removed from the pump assembly 150 can facilitate or improve the process of replacing the covering or the pump, if necessary. Some pump embodiments disclosed herein may be configured to have any suitable connection between the tubing and the pump.

[0024] In some embodiments, the pump assembly 150 may be configured to deliver a negative pressure of approximately -80 mmHg, or between about -20 mmHg and -200 mmHg. Note that these pressures are relative to normal ambient atmospheric pressure, i.e., -200 mmHg may actually be about 560 mmHg. The pressure range may be between about -40 mmHg and -150 mmHg. Alternatively, a pressure range up to -75 mmHg, up to -80 mmHg, or above -80 mmHg may be used. A pressure range below -75 mmHg may also be used. Alternatively, a pressure range of approximately -100 mmHg or even above 150 mmHg may be provided by the pump assembly 150. In some embodiments, the pump assembly 150 is configured to provide continuous or intermittent negative pressure therapy. Continuous therapy may be delivered above -25mmHg, -25mmHg, -40mmHg, -50mmHg, -60mmHg, -70mmHg, -80mmHg, -90mmHg, -100mmHg, -120mmHg, -140mmHg, -160mmHg, -180mmHg, -200mmHg, or below -200mmHg. Intermittent therapy may be delivered between low and high negative pressure settings. The low setpoint may be set above 0 mmHg, 0 mmHg, -25 mmHg, -40 mmHg, -50 mmHg, -60 mmHg, -70 mmHg, -80 mmHg, -90 mmHg, -100 mmHg, -120 mmHg, -140 mmHg, -160 mmHg, -180 mmHg, or below -180 mmHg. The high setpoint may be set above -25 mmHg, -40 mmHg, -50 mmHg, -60 mmHg, -70 mmHg, -80 mmHg, -90 mmHg, -100 mmHg, -120 mmHg, -140 mmHg, -160 mmHg, -180 mmHg, -200 mmHg, or below -200 mmHg. During intermittent treatment, negative pressure at a low setting can be delivered for a first duration, and at the end of the first duration, negative pressure at a high setting can be delivered for a second duration. At the end of the second duration, negative pressure at the low setting can be delivered. The first and second durations can be the same or different values.The first and second durations can be selected from the following ranges: less than 2 minutes, 2 minutes, 3 minutes, 4 minutes, 6 minutes, 8 minutes, 10 minutes, or more than 10 minutes. In some embodiments, switching between the low and high setting values ​​can be performed according to a step waveform, a square wave, a sine waveform, or the like.

[0025] In some embodiments, the TNP system 100 may include multiple wound dressings connected to the pump assembly 150. The performance and wound healing capabilities (such as fluid management) of a TNP system with multiple wound dressings with pump assembly 150 can match or exceed the performance and wound healing capabilities of a standard single wound dressing with a single pump setup.

[0026] In operation, the wound filler 130 is inserted into the wound cavity 110 and the wound cover 120 is placed to seal the wound cavity 110. The pump assembly 150 provides a source of negative pressure to the wound cover 120 that is transmitted through the wound filler 130 to the wound cavity 110. Fluid (e.g., wound exudate) may be drawn through the conduit 140 and stored in the canister. In some embodiments, the fluid is absorbed by the wound filler 130 or one or more absorbent layers (not shown).

[0027] Wound dressings that may be utilized with the pump assembly and other embodiments of the present application include Renasys-F, Renasys-G, Renasys AB, and Pico dressings available from Smith & Nephew. Any of the dressings described herein may be used with Smith & Nephew's Renasys soft port connector or interface between the dressing and the pump assembly. For example, a Renasys soft port connector may be positioned in the flow path 140 and serve as a port for the wound dressing. In other embodiments, other suitable wound dressings may be utilized.

[0028] Pump Assembly and Canister FIG. 2 illustrates a front view 200 of a pump assembly 230 and a canister 220 according to some embodiments. As illustrated, the pump assembly 230 and the canister are connected, thereby forming a TNP device or system. The pump assembly 230 includes one or more indicators, such as a visual indicator 202 configured to indicate an alarm and a visual indicator 204 configured to indicate a status of the TNP system. The indicators 202 and 204 can be configured to alert a user, such as a patient or a healthcare provider, of various operational or fault conditions of the system, including alerting the user of a normal or proper operating condition, a pump failure, power or a power failure supplied to the pump, detection of a leak in the wound cover or flow path, a suction blockage, a no-flow condition, a canister full condition, or any other similar or suitable condition, or combination thereof. The pump assembly 230 can include additional indicators. The pump assembly can use a single indicator or multiple indicators. Any suitable indicators can be used, such as visual indicators, audio indicators, tactile indicators, etc. The indicator 202 may be configured to indicate a warning condition, such as, for example, a full canister, low power, a dislodged conduit 140, a broken seal in the wound seal 120, etc. The indicator 202 may be configured to display a red flashing light to attract the user's attention. The indicator 204 may be configured to signal a status of the TNP system, such as, for example, that therapy delivery is normal, a leak has been detected, etc. The indicator 204 may be configured to display one or more different colors of light, such as green, yellow, etc. For example, a green light may be emitted when the TNP system is operating properly and a yellow light may be emitted to indicate a warning.

[0029] The pump assembly 230 includes a display or screen 206 mounted in a recess 208 formed in the case of the pump assembly. The display 206 may be a touch screen display. The display 206 may support playing audiovisual (AV) content, such as instructional videos. As described below, the display 206 may be configured with several screens or graphical user interfaces (GUIs) to configure, control, and monitor the operation of the TNP system. The pump assembly 230 includes a grip portion 210 formed in the case of the pump assembly. The grip portion 210 may be configured to assist a user in holding the pump assembly 230, for example, during removal of the canister 220. The canister 220 may be replaced with another canister, for example, when the canister 220 is filled with fluid.

[0030] The pump assembly 230 includes one or more keys or buttons 212 configured to allow a user to operate and monitor the operation of the TNP system. As illustrated, buttons 212a, 212b, and 212c are included. Button 212a may be configured as a power button for turning pump assembly 230 on / off. Button 212b may be configured as a play / pause button for delivery of negative pressure therapy. For example, pressing button 212b may start therapy and then pressing button 212b may pause or end therapy. Button 212c may be configured to lock display 206 or buttons 212. For example, pressing button 212c may prevent a user from unintentionally altering the delivery of therapy. Pressing button 212c may release control. In other embodiments, additional buttons may be used or one or more of illustrated buttons 212a, 212b, or 212c may be omitted. Multiple key presses or sequential key presses can be used to operate the pump assembly 230.

[0031] The pump assembly 230 includes one or more latch recesses 222 formed in the cover. In an exemplary embodiment, two latch recesses 222 may be formed on opposite sides of the pump assembly 230. The latch recesses 222 may be configured to allow attachment and detachment of the canister 220 using one or more canister latches 221. The pump assembly 230 includes an air outlet 224 for removing and escaping air from the wound cavity 110. Air entering the pump assembly may pass through one or more suitable filters, such as an antibacterial filter. This may maintain the reusability of the pump assembly. The pump assembly 230 includes one or more strap attachments 226 for connecting a carrying strap to the pump assembly 230 or for attaching a cradle. In an exemplary embodiment, two strap attachments 226 may be formed on opposite sides of the pump assembly 230. In some embodiments, various of these features are omitted or various additional features are added to the pump assembly 230.

[0032] The canister 220 is configured to hold fluid (e.g., exudate) to be removed from the wound cavity 110. The canister 220 includes one or more latches 221 for attaching the canister to the pump assembly 230. In an exemplary embodiment, the canister 220 includes two latches 221 on either side of the canister. The exterior of the canister 220 may be formed from a matte plastic such that the canister is substantially opaque and the contents of the canister are substantially hidden in a plan view. The canister 220 includes a grip portion 214 formed within the canister's casing. The grip portion 214 may be configured to allow a user to hold the pump assembly 220, such as during removal of the canister from the device 230. The canister 220 includes a substantially transparent window 216, which may also include volumetric graduations. For example, the 300 mL canister 220 shown includes graduations of 50 mL, 100 mL, 150 mL, 200 mL, 250 mL, and 300 mL. Other embodiments of the canister can hold different amounts of fluid and include different graduation scales. For example, the canister can be an 800 mL canister. The canister 220 includes a tubing channel 218 for connecting to a conduit 140. In some embodiments, one or more features, such as the grip portion 214, are omitted or various additional features are added to the canister 220. Any of the disclosed canisters may include a solidifying agent or may omit a solidifying agent.

[0033] Electronics and Software FIG. 3 illustrates an electrical components schematic 300 of a pump assembly, such as pump assembly 230, according to some embodiments. The electrical components may operate to accept user input, provide output to a user, operate the pump assembly and TNP system, provide network connectivity, and the like. The electrical components may be mounted on one or more printed circuit boards (PCBs). As illustrated, the pump assembly may include multiple processors. It may be advantageous to utilize multiple processors to apportion or allocate various tasks to the various processors. A first processor may be responsible for user activities, and a second processor may be responsible for controlling the pump. In this manner, activities controlling the pump that may require a higher level of responsiveness (corresponding to a higher risk level) may be offloaded to a dedicated processor, thereby not being interrupted by user interface tasks that may take longer to complete due to user interaction.

[0034] The pump assembly may include a user interface processor or controller 310 configured to operate one or more components, such as the display 206, buttons 212, etc., to accept user input and provide output to the user. Inputs to and outputs from the pump assembly may be controlled by an input / output (I / O) module 320. For example, the I / O module may receive data from one or more ports, such as serial, parallel, hybrid ports, etc. The processor 310 also receives data and provides data to one or more expansion modules 360, such as one or more USB ports, SD ports, compact disc (CD) drives, DVD drives, FireWire ports, Thunderbolt ports, PCI Express ports, etc. The processor 310, along with other controllers or processors, stores data in one or more memory modules 350, which may be internal or external to the processor 310. Any suitable type of memory may be used, including volatile or non-volatile memory, such as RAM, ROM, magnetic memory, solid-state memory, magnetoresistive random access memory (MRAM), etc.

[0035] In some embodiments, the processor 310 may be a general-purpose controller, such as a low-power processor. In other embodiments, the processor 310 may be an application-specific processor. The processor 310 may be configured as a "central" processor within the electronic architecture of the pump assembly, where the processor 310 may coordinate the operation of other processors, such as a pump control processor 370, a communications processor 330, and one or more additional processors 380 (e.g., a processor for controlling the display 206, a processor for controlling the buttons 212, etc.). The processor 310 may run a suitable operating system, such as Linux, Windows CE, VxWorks, etc.

[0036] The pump control processor 370 may be configured to control the operation of the negative pressure source or pump 390. The pump 390 may be a suitable pump, such as a membrane pump, a peristaltic pump, a rotary pump, a rotary vane pump, a scroll pump, a screw pump, a liquid ring pump, a pump operated by a piezoelectric transducer (e.g., a diaphragm pump), a voice coil pump, or the like. The pump control processor 370 may use data received from one or more pressure sensors to measure pressure within the fluid flow path, calculate fluid flow rates, and control the pump. The pump control processor 370 may control actuators, such as a pump motor, such that a desired level of negative pressure is achieved within the wound cavity 110. The desired level of negative pressure may be selected by a pressure setting or a user. In various embodiments, the pump control processor 370 controls the pump actuator (e.g., a pump motor) using pulse width modulation (PWM). The control signal for driving the pump actuator may be a 0-100% duty cycle PWM signal. The pump control processor 370 may perform flow rate calculations and detect various conditions within the flow path. The pump control processor 370 may communicate information to the processor 310. The pump control processor 370 may include internal memory or may utilize the memory 350. The pump control processor 370 may be a low power processor.

[0037] The communication processor 330 may be configured to provide wired or wireless connectivity. The communication processor 330 may utilize one or more antennas 340 to transmit and receive data. The communication processor 330 may provide one or more of the following connection types: Global Positioning System (GPS) technology, cellular connectivity (e.g., 2G, 3G, LTE, 4G), Wi-Fi connectivity, Internet connectivity, etc. The connectivity may be used for various activities such as pump assembly location tracking, asset tracking, compliance monitoring, remote selection, uploading logs, alerts, and other operational data, adjusting treatment settings, software or firmware upgrades, etc. The communication processor 330 may provide dual GPS / cellular functionality. The cellular functionality may be, for example, 3G functionality. In such a case, if the GPS module is unable to establish a satellite connection due to various factors such as atmospheric conditions, building or terrain interference, satellite geometry, etc., the location of the device may be determined using a 3G network connection, such as by using cellular authentication, triangulation, forward link timing, etc. The pump assembly may include a SIM card and may obtain SIM-based location information.

[0038] The communications processor 330 may communicate information to the processor 310. The communications processor 330 may include internal memory or may utilize the memory 350. The communications processor 330 may be a low power processor.

[0039] In some embodiments, the pump assembly can track and store various data, such as one or more of positioning data, therapy parameters, logs, device data, etc. The pump assembly can track and log therapy and other operational data. The data can be stored in memory 350, for example.

[0040] In some embodiments, using the connection provided by the communications processor 330, the device can upload any data stored, maintained, and / or tracked by the pump assembly. Information can be uploaded to a remote computer or server, including, for example, an activity log including therapy delivery information, such as therapy duration, an alarm log including alarm type and time of occurrence, an error log including internal error information, transmission errors, etc., therapy duration information, which may be calculated by hour, day, etc., total therapy time including therapy duration since a particular therapy program or programs were first applied, lifetime therapy information, device information, such as serial number, software version, battery level, etc., device location information, patient information, etc. The device can also download therapy selections, as well as various operational data, such as parameters, firmware and software patches and upgrades. The pump assembly can provide internet browsing capabilities using one or more browser programs, email programs, application software (e.g., apps), etc.

[0041] In some embodiments, the communications processor 330 may use the antenna 340 to communicate the location of the pump assembly, such as the location of the housing of the pump assembly, to other devices in close proximity (e.g., within 10, 20, or 50 meters, etc.) of the pump assembly. The communications processor 330 may communicate one-way or two-way with other devices, depending on the implementation. Communications transmitted by the communications processor 330 may also include identification information to uniquely identify the pump assembly relative to one or more other pump assemblies in the vicinity of the pump assembly. For example, the identification information may include a serial number or a value derived from the serial number. The signal strength of the communications transmitted by the communications processor 330 may be controlled (e.g., maintained at a constant or substantially constant level) to allow another device to determine a distance to the pump assembly, such as the distance between the device and the pump assembly.

[0042] In some embodiments, the communications processor 330 can communicate with other devices in the vicinity of the pump assembly such that the communications processor 330 itself can determine the distance from the pump assembly to the other devices. In such embodiments, the communications processor 330 can track and store the distance from the pump assembly to the other devices or provide an indication of the change in distance over time, and the communications processor 330 can later provide this information to the other devices. For example, the communications processor 330 can determine the amount of time that the pump assembly has been removed from the coverage area of ​​the device and then report this time to the device when it returns to the coverage area.

[0043] Flexible Suction Adapter 4A-6 illustrate an embodiment of a negative pressure wound treatment system 5501 similar to the embodiment illustrated in FIG. 1. Here, the system 5501 may include a flexible suction adapter 5500 (sometimes referred to as a fluid connector) having a bridge portion 5502 having a proximal end 5503 and a distal end 5505, and an applicator 5520 at the distal end 5505 of the bridge portion 5502 forming the flexible suction adapter 5500. A connector 5504 is preferably disposed at the proximal end 5503 of the bridge portion 5502 to connect to at least one of the channels 5512 and / or 5516, as shown in FIG. 4B. A cap 5536 may be provided with the system 5501 (and in some cases may be attached to the connector 5504, as illustrated). The cap 5536 may be useful in preventing fluid from leaking out of the proximal end 5503. The system 5501 may include a source of negative pressure, such as a pump or negative pressure unit 5534 capable of providing negative pressure. The pump may preferably comprise a canister or other container that stores wound exudate and other fluids that may be removed from the wound. In some embodiments, the pump 5534 may be the pump 200 described in connection with FIG. 2. In some embodiments, the pump 5534 may be a RENASYS GO pump sold by Smith & Nephew. The pump 5534 may be connected to the connector 5504 via a tube 5540. In use, the applicator 5520 is placed across an opening 5535 formed in a drape 5531, which is placed over a suitably prepared wound 5530, which in some cases may be filled with a wound packing material such as foam or gauze. The pump 5534, which is connected to the connector 5504 via a tube 5540, then activates the pump, thereby providing negative pressure to the wound. The application of negative pressure may be performed until a desired level of healing of the wound 5530 is achieved.

[0044] In some embodiments, the bridge portion 5502 may comprise a top layer channel material or layer 5512 positioned between the top layer 5510 and the middle layer 5514, and a bottom channel material or layer 5516 positioned between the middle layer 5514 and the bottom layer 5518. Preferably, the layers 5510, 5514, and 5518 have elongated portions extending between the proximal and distal ends and may comprise a fluid impermeable material, for example a polymer such as polyurethane. Of course, the layers 5510, 5514, and 5518 may each be constructed from different materials, including semi-permeable materials. In some embodiments, one or more of the layers 5510, 5514, and 5518 may be at least partially transparent. As shown in FIG. 5B, the top layer 5510 and the bottom layer 5518 may be curved, curled, or outwardly convex over most of their lengths. During assembly, for example, layers 5510, 5514, and 5518 may be sandwiched together and the layers welded or glued together. In doing so, the proximal ends of channels 5512 and 5516 may be sandwiched between these layers, thus partially compressing the proximal ends of channels 5512, 5516 and stretching layers 5510, 5514, 5518 over these aforementioned proximal ends. Of course, the proximal ends of the material used in bridge portion 5502 are not necessarily rounded or curved, but rather they may be substantially squared and kept straight, as shown in FIG. 6.

[0045] The upper channel layer 5512 and the lower channel layer 5516 are preferably elongated layers extending from the proximal end 5503 to the distal end 5505, and each preferably comprises a porous material including, for example, an open cell foam such as polyethylene or polyurethane. In some embodiments, one or more of the upper channel layer 5512 and the lower channel layer 5516 may be comprised of, for example, a knitted or woven spacer fabric (such as a knitted polyester 3D fabric, Baltex 7970.RTM., or Gehring 879.RTM.) or a nonwoven material. Suitable materials may also include terry or loop pile materials. The fibers are not necessarily woven and may include felt and flock fiber materials (including materials such as Flotex.RTM.). The material selected may preferably be placed to direct wound exudate away from the wound, transfer negative pressure and / or expelled air to the wound site, and may also provide some degree of kink or occlusion resistance to the channel layers 5512 and 5516, as described below. In one embodiment, the upper channel layer 5512 may comprise an open cell foam such as polyurethane, and the lower channel layer may comprise a fabric as described herein. In another embodiment, the upper channel layer is optional, and the system may instead comprise an open upper channel. In the embodiment shown in FIG. 5B, the upper channel layer 5512 may have a curved, rounded or upwardly convex upper surface and a substantially flat lower surface, and the lower channel layer 5516 may have a curved, rounded or downwardly convex lower surface and a substantially flat upper surface.

[0046] In some embodiments, the fabric may have a three-dimensional (3D) structure, with one or more types of fibers forming a fibrous extending structure in all three dimensions. Such fabrics may aid in wicking, fluid transport, and / or negative pressure transmission in some cases. To prevent channels 5512 and / or 5516 from displacing or twisting while contained within system 5501, which may impair the performance of the respective channels under negative pressure, in some embodiments it may be preferable to glue or otherwise secure channels 5512 and / or 5516 to one or more of layers 5510, 5514, and 5518. In certain embodiments, these materials remain open and are capable of transmitting negative pressure to the wound area under normal pressures used in negative pressure treatments, e.g., 40-150 mmHg, although higher and lower values ​​are possible. In some embodiments, the fabric may comprise several layers of material stacked or laminated on top of each other, which may be useful in some cases to prevent the channel 5516 from collapsing under negative pressure. In other embodiments, the fabric used for the channel 5516 may be 1.5 mm to 6 mm thick, more preferably the fabric may be 3 mm to 6 mm thick and may consist of one or several individual fabric layers. In other embodiments, the channel 5512 may be 1.2 to 3 mm thick, preferably thicker than 1.5 mm. Additionally, as previously described, the material used for the system 5501 is preferably comfortable and soft, which may help to avoid pressure sores and other complications that may result from a wound treatment system being pressed against the patient's skin. Further examples of 3D fabrics are described below in Figures 7A-C.

[0047] Preferably, the distal ends of layers 5510, 5514, and 5518, as well as channel layers 5512 and 5516, may be expanded at their distal ends (which are disposed over the wound site) to form a "teardrop" or other expanded shape. The distal ends of at least layers 5512, 5514, 5516, and 5518 may also include at least one opening therethrough. This opening may be useful not only for drainage of wound exudate and application of negative pressure to the wound, but also during manufacture of the device, as these openings may be used to properly align their respective layers.

[0048] With additional reference to Figures 5B, C and 6, a channel connector 5506 is provided at the proximal end 5503 of the bridge portion 5502, the channel connector 5506 being preferably configured to be embedded in the lower channel layer 5516 to form a secure fluid connection. The channel connector 5506 may, in some embodiments, be inserted into a pre-made cavity formed in the channel 5516, which may be cut out or in the form of a tongue and groove joint, as shown in Figure 6. In some embodiments, the channel connector 5506 may be one of the connectors described in Figures 8A and B below. With one end of the channel connector 5506 embedded in the lower channel layer 5516, the other end of the channel connector 5506 may, in one embodiment, be connected or in communication with a connector tube 5507, although in some embodiments, the channel connector 5506 may be directly connected to a connector 5504 or a tube 5540 that is otherwise connected to a negative pressure source. When using a connector tube 5507, the resulting assembly may have the connector 5504 attached to the connector. The cap 5536 may be secured to the suction adaptor via, for example, a cap leash 5527 secured with a ring disposed on the exterior surface of the connector tube 5507. The cap 5536 may be used, for example, to cover the end of the suction adaptor with the connector 5504 to prevent exudate and other wound fluids from leaking out. The connector 5504 is preferably configured to connect with a tube 5540 connected to a negative pressure source. The connector 5504 may include, for example, a lip or other such structure that helps secure the connector 5504 to the tube 5540 and / or the cap 5536, although it may be understood that other connector types are possible, including quick disconnect couplings, luer locks, Christmas trees, and other such connectors.

[0049] The top layer 5510 may comprise additional material extending downward, preferably at least below the thickness of the bridge portion 5502, which may be used to bond or weld to other layers to form a fluid tight seal. More specifically, during assembly, the top layer 5510 may be attached to the bottom layer 5518 to form a fluid tight seal, for example, by melting, welding, or with an adhesive (with the exception of openings at the distal and proximal ends). The middle layer 5514 is preferably attached to the top layer 5510 and the bottom layer 5518. In some embodiments, it may be preferred to attach or glue the connectors 5504 and / or 5506, as well as the tube 5507 to at least one of the layers 5510, 5514, 5518 to form a fluid tight connection. To provide a more secure connection, some embodiments may also be provided with weld points 5532 made on the bottom layer 5518. The lower channel 5516 may have a hole or opening made therethrough which may be used to weld it to the lower layer 5518 via weld points 5532. This welding of the lower channel 5516 to the lower layer 5518 via weld points 5532 made through holes 5533 may thus help to prevent the various layers and channels from shifting or displacing. Of course, it will be understood that other fastening means may be used, such as, for example, adhesives, and that such arrangements may also be used with the upper channel 5512.

[0050] In certain embodiments, for example, as shown in FIGS. 5A-6, a controlled gas leak 5524 (which may also be referred to as a gas leak, air leak, or controlled air leak) may be disposed on the bridge portion 5502, for example, at a proximal end thereof. The air leak 5524 may include an opening or channel extending through the upper layer 5510 such that the air leak 5524 is in fluid communication with the upper channel 5512. Upon application of suction to the suction adapter 5500, gas (e.g., air) may enter through the gas leak 5524 and travel from the proximal end 5503 along the upper channel 5512 to the distal end 5505. The gas may then be drawn into the lower channel 5516 by passing through openings through the distal ends of layers 5512, 5514, 5516, and 5518. The air leak 5524 preferably includes a filter 5525. Preferably, the air leak 5524 is located at the proximal end of the bridge portion 5502 to minimize the possibility of wound exudate or other fluids contacting and blocking or obstructing the air leak 5524 or its filter 5525. In some embodiments, this filter 5525 is a microporous membrane capable of excluding microorganisms and bacteria and filtering particles larger than 45 μm. Preferably, the filter 5525 is capable of filtering out particles larger than 1.0 μm, and more preferably, particles larger than 0.2 μm. Advantageously, some embodiments may provide a filter 5525 that is at least partially chemically resistant, for example, to water, common household liquids such as shampoo, and other surfactants. In some embodiments, reapplication of vacuum to the suction adapter 5500 and / or wiping the exposed outer portion of the filter 5525 may be sufficient to remove any foreign matter blocking the filter 5525. The filter 5525 may be constructed of a suitably resistant polymer, such as acrylic, polyethersulfone, or polytetrafluoroethylene, and may be oil-repellent and / or hydrophobic. In some embodiments, the filter 5525 may also include a support backing layer, for example a nonwoven polyester support.Preferably, the gas leak 5524 is capable of providing a relatively constant gas flow that does not increase significantly as additional negative pressure is applied to the system 5501. In embodiments of the suction adapter 5500, as additional negative pressure is applied, the gas flow through the gas leak 5524 increases, but preferably this increased gas flow is minimized and does not increase in proportion to the negative pressure applied thereto.

[0051] The filter 5525 provided in the controlled air leak 5524 in certain embodiments may be useful in the system 5501 for use with more ambulatory and active patients. For example, a chemically resistant filter may allow the patient to bathe or shower without compromising the function of the filter when reconnected to a negative pressure source. Any blockage or fluid blocking the air leak 5524 may then be removed, for example, by wiping the filter 5525 or reapplying negative pressure to the suction adapter 5500. Such a system also has the advantage that the system 5501 and any associated wound dressing material, if present, do not need to be removed and then reapplied if the patient needs to be disconnected from the negative pressure source, for example, associated with bathing. This entails significant benefits in improving the cost efficiency and ease of use of the present treatment system.

[0052] The suction adapter 5500 is preferably constructed to provide constant fluid flow even when the suction adapter 5500 is twisted or weighted. For example, when used on a patient, the bridge portion 5502 may fold on itself or otherwise cause the patient to roll over and thus rest on at least a portion of the suction adapter 5500. Typically, prior art dressings and fluid connectors may be blocked or ineffective in such situations, potentially contributing to complications such as pressure ulcers. However, certain embodiments now provide improved occlusion resistance when twisted or weighted. Preferably, by using the channel layers 5512 and 5516 as described above, and more preferably by using the foam channel layer 5512 and fabric channel layer 5516, the suction adapter 5500 can maintain a flow rate through the air leak 5524 of at least 0.08 L / min, preferably 0.12 L / min, while negative pressure is applied through a negative pressure source. Further embodiments also provide that the suction adapter 5500 can handle at least 10 L / day, or 6.9 ml / min of fluid exudate drainage from the wound site through the lower channel 5516. Certain embodiments provide the suction adapter 5500 to maintain these flow rates even with a 12 kg weight, for example, pushing down on the bridge portion through a 1 inch diameter rod. In some embodiments, these flow rates are maintained while the bridge portion 5502 is twisted on itself with the same weight, or with a 4.75 kg weight, for example, placed directly on the folded area. The suction adapter 5500 can preferably withstand being folded and twisted even over an extended period of time, for example, 40 hours or more, without showing any degradation in performance (e.g., flow rate) compared to its performance before being folded and twisted. Preferably, embodiments of the suction adapter 5500 can also deliver and maintain negative pressure at the wound close to the negative pressure level of the negative pressure source. For example, an acceptable level of pressure maintained at the wound may be within +-.25 mmHg of the negative pressure set by the negative pressure source, and this pressure is preferably maintained at this level within 95% of the time that the suction adapter 5500 applies negative pressure.Acceptable pressure levels can include a pressure range of 40 to 120 mmHg, although a level of 200 mmHg has been used successfully.

[0053] With additional reference to Figures 4A-5B and 6, the suction adapter 5500 also comprises an applicator 5520 designed to be placed on the wound site. Preferably, the applicator 5520 comprises a flexible layer 5550, such as polyethylene or polyurethane, with a layer of adhesive on its lower (wound-facing) side. Optionally, a protective release layer 5529 may be placed on the adhesive layer, which is removable prior to use. In some embodiments, due to the flexibility of the layer 5550, a more rigid removable backing layer 5552 may be provided on the upper side of the applicator 5520 to facilitate handling of the applicator 5520. The applicator 5520 preferably includes an attachment point for the bridge 5502 at the distal end 5505, such as, for example, using a section of double-sided adhesive tape 5528. The double-sided adhesive tape 5528 may be protected by an additional protective release layer that is removed prior to adhering the bridge 5502 to the applicator 5520. As will be appreciated, different attachment methods are contemplated, such as, for example, heat sealing, welding, or a suitable adhesive. Some embodiments may also permit manufacture of the bridge 5502 and applicator 5520 as a single unit without the need for separate attachment means. The applicator 5520 preferably includes at least one opening 5526 therethrough that is designed to be placed over the wound site and can fluidly connect the wound site to a source of negative pressure and an air leak while also functioning as a conduit for drawing wound exudate from the wound site.

[0054] In use, and with reference to Figures 4A and B, the system 5501 may be used in a manner similar to other embodiments previously disclosed herein, such as the system 100 described in connection with Figure 1. The wound site 5530 is cleaned and prepared in a suitable manner, and wound packing material is placed at the wound site, if necessary, preferably followed by the drape 5531. An opening 5535 through the drape to the wound site is then created, although some embodiments may have a pre-made opening 5535. The operator may then position the applicator portion 5520 over the opening 5535. After removing the backing layer 5529 (if present) from the adhesive layer at the bottom of the applicator portion 5520, the applicator is sealed to the drape 5531, and the backing layer 5552 (if present) is also removed from the applicator portion 5520. A fluid conduit, such as a tube 5540, may then be connected to the connector 5504. The tube 5540 may also be connected to the connector 5504 prior to application of the applicator to the wound site. The fluid conduit is connected to a negative pressure source 5534, preferably having a container suitable for containing wound exudate interposed therebetween. Application of negative pressure may then be performed to the wound site 5530 until the wound site has progressed to a desired level of healing.

[0055] During use of the system 5501, wound exudate from the wound site 5530 is drawn by negative pressure through the lower channel layer 5516. The gas leak 5524 can allow gas (such as air) to pass through the upper channel layer 5512 by passing through openings through the distal ends of layers 5512, 5514, 5516 and 5518. The negative pressure draws gas passing through the upper channel layer into the lower channel layer 5516 toward a negative pressure source or pump. In some embodiments, the controlled gas leak 5524 provides a constant flow of air through the suction adapter 5500, which can then be used to determine if a blockage or leak exists. Causes of blockages can include, for example, a situation where the lower channel 5516 is blocked with wound debris. Causes of leaks can include, for example, improper sealing of a drape over the wound site or physical damage to the suction adapter 5500 resulting in excessive gas leakage into the system. A blockage or leak may be determined in certain embodiments by measuring the speed of the pump while it functions to maintain a constant negative pressure. The pump speed may also be measured indirectly by measuring the amount of voltage or signal sent to the pump.

[0056] 7A-C illustrate diagrams of 3D fabrics that may be used in various embodiments described herein, such as the bridge portion 5502 of the suction adapter illustrated in FIGS. 4A-6. While other porous materials such as foams may be used in the embodiments described herein, such as the upper channel 5512 and / or the lower channel 5516 shown in FIGS. 5B and C, the use of 3D fabrics may be advantageous in some situations. Certain 3D fabrics have been found to perform well in conveying negative pressure and wound exudate from the fluid suction adapter, even during compression, such as when the patient's weight is directly on the suction adapter or when negative pressure is applied and / or when the fluid suction adapter is twisted or folded. Some 3D fabrics that have been found to perform acceptably include woven polyester 3D fabrics, Baltex 7970.RTM, Gehring 879.RTM, or Coolmax.RTM. Of course, other fibers and fabric types may be used in part or in whole to make the 3D fabric, including, but not limited to, polyamides such as nylon, viscose, cotton, and other synthetic microfibers. The 3D fabric may also be constructed at least in part from fibers such as Nomex.RTM. and Kevlar.RTM. Other types of fabrics and materials disclosed elsewhere herein may also be used.

[0057] In one embodiment, as shown in Figures 7A-C, the 3D fabric may include a bottom surface 5603, a top surface 5605, and an open central region 5607. Figure 7A illustrates the bottom (wound-facing) surface 5603 of the 3D fabric, which may be woven to form oval or elliptical openings 5611 that extend longitudinally across the fabric. In one embodiment, the oval or elliptical openings 5611 represent or provide an open area of ​​10-45% (or about 10% to about 45%), more preferably 10% to 30% (or about 10% to about 30%) of the surface area of ​​the bottom layer. Here, the fibers are woven (e.g., by warp knitting) to also include these larger openings or pores that allow for bulk transport of wound fluid in addition to wound fluid that is carried along the fibers by capillary action of the fibers. Optionally, openings formed at the distal ends of the 3D fabric (illustrated in Figures 5B and 6) may also aid in bulk evacuation of wound debris and fluids.

[0058] FIG. 7B illustrates a top surface 5605 of a 3D fabric that may be used as described herein. In one embodiment, this top surface 5605 does not have the larger oval openings 5611 of the bottom surface 5603, but may have openings 5613 defined by fibers that extend longitudinally and generally laterally or at angles across the width of the fabric. As illustrated, these openings are generally diamond shaped. In one embodiment, these openings 5613 may represent or provide a larger open area than the openings, for example, between 30%-50% (or about 30%-about 50%). Of course, it will be understood that the fabrics presented herein are non-limiting examples and different fabric configurations and orientations are possible, for example, the top surface 5605 is positioned facing downwards to face the wound and the bottom surface 5603 is positioned facing upwards.

[0059] FIG. 7C shows a cross section of the 3D fabric (the bulb-like protrusions on the vertical fibers in the fabric are an artifact of the cutting process). The vertically extending fibers 5609 may be woven to extend through a central open area 5607 while also being connected to the bottom layer 5603 and the top layer 5605. The fibers 5609 present in the open middle layer 5607 are preferably stiff enough to help prevent compression of the fabric. As shown in this figure, and without intending to be bound by theory, 3D fabrics found to perform well often include a larger open area 5607 in the center that allows exudates and other fluids to be effectively transported away from the wound site while under application of negative pressure, while the more densely woven outer layers 5603, 5605 may help provide additional tension and capillary wicking action. For example, the middle layer may include more than (or about) 50% open volume. Of course, the resulting fabric cannot be too thick or made of too stiff fibers, as the resulting suction adapter and system may not remain flexible enough for comfortable use by the patient.

[0060] It will often be advantageous to tailor the performance characteristics of the 3D fabric during use to take into account the various requirements of the suction adapter. In particular, the flow rate of exudate through the fabric, for example when under compression, can be simplified by considering the porosity of the fabric. In such a situation, without intending to be bound by theory, again, the porosity of the fibers, and therefore the space available for fluid to pass through, can be determined in part by the knit pattern of the fibers used to create the 3D fabric, the thickness of the fibers used therein, and their respective stiffness and hardness (particularly when under compression). The fibers may also be modified by the surface characteristics (fibers can be flat or textured) and the number of fibers or filaments used in the resulting fabric. Compression resistance can be influenced by the choice of fibers or monofilaments used in the vertical axis of the fabric, and generally stiffer materials can improve compression resistance on this axis. Other material properties, such as hydrophobicity, may play a role. In some cases, it may be beneficial to treat the fibers to be hydrophilic, for example with a hydrophilic polymer, to improve wicking of fluids. A preferred embodiment of the 3D fabric used with certain suction adapters has been found to work well when the Baltex.RTM. fabric is treated in this manner. Other possible treatments may include a lipophilic coating to prevent protein from adhering and building up during use, which can cause blockage and loss of pressure to the wound site.

[0061] The flow rate through the 3D fabric while under application of negative pressure can be approximated by considering each opening as a separate orifice plate subject to Bernoulli's principle while under laminar flow. To simplify the calculation, the area of ​​the openings for a given area of ​​the 3D fabric may be used. Thus, the 3D fabric can be optimized to achieve a good balance between the required compression resistance and the flow rate that occurs under application of negative pressure. Further optimization is also performed with the stiffness and flow rate of the 3D fabric, which are tailored for the application in the embodiments described herein. Optimization of the properties and dimensions of the 3D fabric also preferably takes into account the balance between the required flow rate and stiffness and the conformability of the fabric, since a fabric that is too stiff may not flex properly and may cause discomfort to the patient. The 3D fabric is preferably designed to yield when compressed against tissue, thereby preventing discomfort and damage, such as tissue compression (e.g., against a patient's bony prominence) and pressure sores that may follow. For example, the dimensions of the fabric may be adjusted for the final use of the suction adapter, smaller for distal extremities such as fingers and larger for the abdomen and burns. Fabrics that are too stiff may function acceptably in larger sizes, but may also lead to pressure sores and other such complications.

[0062] In practice, and as described herein, the flow rate through an embodiment of the suction adapter using the 3D fabric should be at least 0.08 L / min, preferably up to 10 L / min, during application of negative pressure, and be able to handle drainage of at least 10 L / day of fluid exudate. Some embodiments of the suction adapter may be configured to handle larger wounds, including abdominal wounds, which in some cases may exude at least 0.5 L / hr, or 12 L / day. In more extreme cases, the pump used (e.g., RENASYS EZ) can drain up to 16 L / min, thereby draining large wounds to a negative pressure level of 120 mmHg within one minute. The pressure drop calculated by the 3D fabric should be minimal, and the level of negative pressure measured at the wound site is preferably within 25 mmHg of the pressure level measured at the negative pressure source. Although the pressure drop increases as the negative pressure applied increases (thus making the 25 mmHg target more difficult to reach), embodiments of the wound treatment system are preferably able to maintain this target pressure up to at least 200 mmHg of negative pressure. The suction adapter and system are preferably able to function within the pressure range required for negative pressure, estimated to be approximately 40 mmHg to 200 mmHg. Pressure ranges above 200 mmHg are possible, but may cause patient discomfort in some cases. The device may also function at lower pressure ranges, such as 20 mmHg, but at such lower pressure levels, the therapeutic effect resulting from the negative pressure may be reduced and the device acts more as a drainage device. Embodiments of the negative pressure treatment system are preferably able to maintain these target pressures at the wound site within 95% of the time that negative pressure is applied to the wound. In some embodiments, the fabric may comprise several layers of material stacked or laminated on top of each other, which may be useful in some cases to prevent the channels 5516 from collapsing under negative pressure application conditions. In other embodiments, the fabric used for channel 5516 may be between 1.5 mm and 6 mm thick, more preferably the fabric may be between 3 mm and 6 mm thick and may consist of one or several individual fabric layers.In other embodiments, the channel 5512 may be 1.2-3 mm thick, preferably thicker than 1.5 mm. Preferably, the 3D fabric can withstand a load of at least 5.3 psi with compression of 10% or less of the fabric's original thickness. Additionally, the 3D fabric can also withstand compression to less than half of its original thickness when subjected to a load of 15 psi.

[0063] In a preferred embodiment, the 3D fabric may be woven from 100% polyester using 150 and 225 denier yarns to obtain a fabric weighing approximately 23-25 ​​ounces per square yard. In these cases, the fabric may be approximately 5.8-6.8 mm thick. The bottom of the fabric may also have several openings or pores 5611 similar to those illustrated in FIG. 7A, which may be elongated, rectangular or oval in shape and oriented longitudinally with their long axis along the fabric. The openings 5611 may be arranged in multiple rows extending lengthwise across the fabric, such as, for example, 2-5 rows, or more preferably, 3 rows, as illustrated in FIG. 7A. The openings 5611 may be spaced equidistant from each other in each of the rows, or may form an alternating pattern from one row to another. In one embodiment, each row may have approximately 6-10 openings, more preferably 8 openings per 2 inches (or approximately 50 mm). Along a given width or transverse dimension of the fabric, the transverse rows formed by the apertures may have a spacing of about 6-10 apertures, more preferably 8 apertures, per 21 / 8 inch (or about 54 mm). In one embodiment, the apertures may have a longitudinal length of about 1 / 16" to about 1" and a width of about 1 / 32" to 1 / 2". In one example, the apertures measure about 1 / 8" (or about 3.2 mm) longitudinally and 1 / 32" (or about 0.79 mm) transversely. In one embodiment, the 3D fabric may have a total length of about 50-100 mm, more preferably about 60 mm, a width of about 5-15 mm, more preferably about 9 mm, and a thickness of about 6 mm.

[0064] The embodiments of the system described herein have been tested and found to perform satisfactorily. Such testing was carried out by constructing a suction adapter from the embodiments described herein. The distal end of the suction adapter was then placed over an opening made on a drape placed over a simulated wound cavity, where a source of simulated wound fluid was provided that was controllable and capable of varying the flow rate of the wound fluid. The simulated wound cavity was also filled with foam or some other wound packing material in some cases. In some tests, the simulated wound fluid was a 5:1 water to glycerol mixture, while in others, filtered horse serum (available from Oxoid, UK) was used. The proximal end of the suction adapter was then connected to a source of negative pressure, in this case a pump. Flow tests and other measurements were then carried out at various negative pressure ranges to simulate exudate flow rates and air leak rates.

[0065] FIG. 8A illustrates an embodiment of a connector 5704 that is similar to the connector 5506 previously described and that may be used to securely connect a negative pressure source to a channel 5716 of a suction adapter such as those described herein. For example, this channel 5716 may be the upper channel 5512, or more preferably, the lower channel 5516 of FIGS. 55-56. Generally, such connectors 5704 may be useful to provide a more secure connection from a negative pressure source to a negative pressure treatment system. The use of these connectors 5704 is optional and may not be necessary in all embodiments described herein. In use, the tube 5740 connected to the connector 5704 may be pulled out or other external force may cause the connector 5704 to move in some way away from the channel 5716 to which it is attached. In such a situation, the application of negative pressure to the wound may be reduced or stopped. Further means for securing the connector 5704 to the rest of the system may include bonding or attaching other layers of the treatment system to the connector 5704, if present, as described above. The connector 5704 may be designed to create a secure connection with the fabric or material used in the channel, and when 3D fabric or 3D knitted materials are used, some embodiments of the connector 5704 are configured to engage or attach with a portion of the material or fiber of the material to create a more secure connection. Preferably, embodiments of the connector 5704 can withstand a pulling force of up to 20 kg such that the connector will detach from the channel it connects to before disconnection and / or failure of the connector occurs. It will be appreciated that other embodiments may be configured to withstand lower pulling forces and may be adjusted to disengage to prevent injury to the patient (e.g., contraction of the suction adapter and / or drain around the limb).

[0066] FIG. 8B illustrates an embodiment of a connector 5704a that includes two or more protrusions 5752 extending longitudinally distally from a preferably cylindrical body of the connector 5704a. The body also includes a central channel 5755 extending longitudinally through the body of the connector 5704a. The protrusions 5752 may further include one or more barbs 5754 attached thereto. Preferably, these barbs 5754 are angled proximally to act as anchors when pressed or inserted into the channel 5716. If the channel 5716 is a 3D fabric or knitted material, the barbs 5754 are configured to engage the fibers therein, creating a more secure connection. At the proximal end of the connector 5704a, a lip 5756, which may be provided in a frusto-conical form, may also be provided for connection to the tube 5740. The tube 5740 may be connected to the connector 5704a (and other connectors described herein) by, for example, a press fit, although other connection means are possible. Tube 5740 may be the same as tube 5507 of FIG. 6, or any other tube used to provide fluid communication with a negative pressure source. Of course, these connector features may be incorporated onto the ends of the tubes used to transmit negative pressure, particularly at the distal end, so that these tubes may be directly connected to the suction adapter system. Examples of such applications in which additional disclosure regarding the foregoing description of connectors may be found include U.S. Patent No. 9,050,398, issued June 9, 2015, entitled “APPARATUSES AND METHODS FOR NEGATIVE PRESSURE WOUND THERAPY,” which is incorporated herein by reference in its entirety.

[0067] Flexible suction adapter with separate air leak 9A-C illustrate an embodiment of a flexible suction adapter 900 similar to the embodiment of the flexible suction adapter 5500 illustrated in and described in conjunction with FIGS. 4A-8B. FIG. 9A illustrates an exploded view of the suction adapter 900, and FIG. 9B shows a top view of the suction adapter 900. Additionally, FIG. 9C illustrates a cross-sectional view of the suction adapter 900. The suction adapter 900 may include a bridge portion 902 having a proximal end 903 and a distal end 905, and an applicator 920 at the distal end 905 of the bridge portion 902 to form the flexible suction adapter 900. The flexible suction adapter is constructed in a similar manner to the flexible suction adapter 5500, and the bridge portion 902 may be preferably constructed from a similar double layer arrangement as previously described. For example, in some embodiments, the bridge portion 902 includes a top channel layer 912 positioned between a top layer 910 and a middle layer 914 , and a bottom channel layer 916 positioned between the middle layer 914 and a bottom layer 918 .

[0068] 9A-C, a controlled gas leak 924 (which may also be referred to as a gas leak, an air leak, or a controlled air leak) may be disposed on the bridge portion 902, for example at a proximal end thereof. The air leak 924 may include an opening or channel that extends through the top layer 910 such that the air leak 924 is in fluid communication with the top channel 912. The air leak 924 may include a filter 925.

[0069] The applicator 920 preferably includes an attachment point for the bridge portion 902 at the distal end 905, such as, for example, using a section of double-sided adhesive tape 928. As will be appreciated, different attachment methods are also contemplated, such as, for example, heat sealing, welding, or a suitable adhesive.

[0070] A connector 904 may be disposed at the proximal end 903 of the bridge portion 902 to connect to at least one of the channels 912 and / or 916. A cap 936 may be provided to the suction adapter 900 (and in some cases may be attached to the connector 904 as shown). As shown in FIG. 9A, a channel connector 906 may be provided at the proximal end 903 of the bridge portion 902, the channel connector 906 preferably configured to be embedded in the lower channel layer 916 to form a secure fluid connection. With one end of the channel connector 906 embedded in the lower channel layer 916, the other end of the channel connector 906 may connect or communicate with a connector tube 907 in one embodiment, although in some embodiments the channel connector 906 may be directly connected to the connector 904 or directly connected to a tube connected to a negative pressure source.

[0071] Each of the components of the suction adapter 900 may be similar to the corresponding components of the suction adapter 5500, and therefore the descriptions of the corresponding components of the suction adapter 5500 previously referred to in this specification also apply to the respective components of the suction adapter 900, except as described below.

[0072] In a similar manner to the suction adapter 5500, an upper fluid passage may be defined by and between an upper layer 910 and a middle layer 914. In some embodiments, as shown in FIG. 9C, the upper layer 910 and the lower layer 918 extend further at the distal end 905 than the middle layer 914 such that the upper fluid passage may be partially defined between the upper layer 910 and the lower layer 918. The upper fluid passage may include an upper channel spacer material or layer 912. The lower fluid passage may include a lower channel spacer material or layer 916. In some embodiments in which the upper layer 910 extends further at the distal end 905 than the middle layer 914, the upper channel spacer layer 912 may also extend further at the distal end 912 than the middle layer 914 and the lower channel spacer layer 916 to support the upper layer 910. In some embodiments, shown in Figures 9A-C, the distal ends of layers 910, 914, and 918, as well as channel layers 912 and 916, may be expanded at their distal ends (which are disposed over the wound site) to form a "teardrop" or other expanded shape. The distal ends of at least layers 912 and 916 may also be provided with at least one opening therethrough. This opening may be useful not only for drainage of wound exudate and application of negative pressure to the wound, but also during manufacture of the device, as these openings may be used to properly align these respective layers. In further embodiments, the upper fluid channel may further include an auxiliary spacer layer 970 disposed below the distal end of the upper channel spacer layer 912 and distal to the distal end of the lower channel spacer layer 916, such that the auxiliary spacer layer 970 supports the distal end of the upper channel spacer layer 912. As shown in FIGS. 9A and 9C, the auxiliary spacer layer 970 can include one or more apertures that can be aligned with one or more apertures at the distal end of the spacer layer 912.

[0073] In some embodiments, as shown in FIGS. 9A and 9C, the suction adapter 900 includes two openings in the bottom layer 918, for example, an air leak channel opening 952 and a suction opening 954, both formed in the bottom layer 918 at the expanded distal end of the bottom layer 918. In some embodiments, the air leak opening 952 and / or the suction opening 954 may be formed as a plurality of smaller holes. As illustrated, the openings 952 and 954 may be spaced apart, with the opening 954 located proximal to the opening 952. Both of these openings may be located on the central longitudinal axis of the bottom layer 918, or one or both openings may not be located on the central longitudinal axis. The applicator 920 may have two openings 962 and 926 configured to align with the air leak channel opening 952 and the suction opening 954.

[0074] As shown in Figure 9C, the air leak channel opening 952 can be fluidly connected to an upper fluid channel with the upper channel spacer layer 912, thereby forming an air leak flow that extends distally from the air leak portion 924 to the air leak channel opening 952. This air leak flow passes through the auxiliary spacer layer 970, as shown in Figure 9C. The suction opening 954 can also be fluidly connected to a lower fluid channel with the lower channel spacer layer 916, thereby forming an suction flow and / or negative pressure source that extends distally from the connector 904.

[0075] In some embodiments, the top layer 910 may form a fluid-tight seal with the middle layer 914 and / or the bottom layer 918, and the middle layer 914 may form a fluid-tight seal with the bottom layer 918, such that the top fluid channel extending distally from the air leak portion 924 to the air leak channel opening 952 may be fluidly separated from the bottom fluid channel extending distally from the connector 904 to the suction opening 954. As shown in FIG. 9C, in some embodiments, the distal end of the middle layer 914 may extend between the auxiliary spacer layer 970 and the bottom channel spacer layer 916 and be sealed with the bottom layer 918, thereby separating the top and bottom fluid channels. The top layer 910, middle layer 914, and bottom layer 918 may be sealed to one another using any means described herein, for example, by melting, welding, or with an adhesive.

[0076] The air leak opening 952 and the suction opening 954 may be spaced sufficiently apart from one another so that wound exudate drawn into the suction opening 954 does not enter the air leak opening 952. In some embodiments, the upper fluid channel may include a filter (not shown) adjacent the air leak opening 952 to prevent ingress of wound exudate into the upper fluid channel and block the upper fluid channel. The filter may be permeable to gas (e.g., air) to allow gas from the gas leak to be provided to the wound dressing, but may be impermeable to liquids or bacteria. The filter disposed at the air leak opening 952 may be similar to the filter 5525 described above.

[0077] In some embodiments, the lower fluid channel may include a filter (not shown) adjacent the suction opening 954. The filter may be configured to substantially prevent wound exudate from entering the lower fluid channel. Preferably, the filter is impermeable to liquids, but may be permeable to gas, and is provided to act as a liquid barrier and ensure that liquids cannot escape the wound dressing, such that a canister to collect wound fluid may not be required between the suction adapter and the negative pressure source. The filter may be hydrophobic. The filter may be attached or sealed to the suction adapter and / or cover film, on the wound dressing. For example, the filter may be molded into the suction adapter 900 or may be adhered to the bottom layer 918 of the suction adapter 900 using an adhesive, such as a UV-curable adhesive.

[0078] The auxiliary spacer 970 may be constructed from any flexible material suitable for the transmission of gas (e.g., air) through a controlled air leak. The auxiliary spacer 970 may be constructed from any material suitable for the upper channel spacer layer 912, 5512 and lower channel spacer layer 916, 5516 described herein, or a nonwoven material, such as, for example, an open cell foam such as polyethylene or polyurethane, or a fabric such as a knit or woven spacer fabric (e.g., knit polyester 3D fabric, Baltex 7970.RTM., or Gehring 879.RTM.).

[0079] In the illustrated embodiment 900 of Figures 9A and 9C, the double-sided adhesive tape 928 is adhered around the suction openings 926 and 954, thereby securing the applicator 920 to the bottom layer 918. However, in some embodiments, the double-sided adhesive tape 928 may be sized and shaped to be adhered around the air leak openings 952 and 962, or both openings 962 / 952 and 926 / 954. In some embodiments, the suction adapter 900 may include an additional double-sided adhesive tape (not shown) similar to the adhesive tape 928 adhered around the air leak openings 952 and 962. In some embodiments, in addition or alternatively to the double-sided adhesive tape(s), the applicator may be attached to the bottom layer 918 using adhesive and / or welding.

[0080] In operation, the embodiment described in Figures 9A-C provides an air leak path extending into the wound dressing that is fluidly separated from the suction flow path extending from the wound dressing to the negative pressure source. This embodiment differs from the embodiment of Figures 5A-6, in which the air leak path fluidly connects with the suction flow path above the wound dressing. In the embodiment of Figures 5A-6, if the opening 5526 is blocked, for example, the suction adapter is not properly positioned over an opening formed in a wound cover placed over a wound, or if the opening 5526 is blocked by wound exudate, the negative pressure source may continue to operate and draw fluid from the suction adapter by drawing gas (e.g., air) from the air leak. This may make it difficult to detect blockage of the suction adapter or misalignment of the suction adapter over the opening in the wound cover. By having an air leak path fluidly separated from the aspiration flow path described herein, if the aspiration opening 926 is blocked, the negative pressure source may stop drawing fluid (e.g., air) from the suction adapter because the air leak will only flow through the wound. This allows for detection of blockage of the suction adapter. Additionally, by isolating the controlled air leak path, it may be easier to measure flow or pressure through the aspiration flow path without interference from the air leak.

[0081] 9A-C illustrate an example of a flexible suction adapter 900 with a fluidically decoupled or separated air leak channel (upper fluid channel) and suction channel (lower fluid channel), other arrangements of the flexible suction adapter 900 with separated air leak and suction channels are possible. For example, the air leak channel and suction channel may be arranged in parallel instead of one channel being placed on top of the other. In some embodiments, two physically separated flexible tubes may be connected to the wound bed, with one tube acting simply as a means to allow permeation from a negative pressure source and the other tube acting solely as an air leak channel to allow air from a controlled air leak to flow into the wound.

[0082] 10 illustrates a diagram of a system 1000 for applying negative pressure according to some embodiments, such as utilizing a suction adapter 900 or any suction adapter with a separated air leak path. As illustrated, the system 1000 includes a negative pressure source 1022 in fluid communication with a wound dressing 1006 via a fluid flow path 1040 to provide negative pressure to one or more wound sites. The fluid flow path 1040 includes a suction adapter 1020 and a tube 1042 connected by a connector 1052. The suction adapter 1020 also includes a gas leak 1012 (also referred to as an air leak) configured to allow gas (e.g., air) to enter the suction adapter 1020.

[0083] As shown in FIG. 10, the suction adapter 1020 includes a calibrated leak path 1026 and a suction path 1024. The suction path 1024 is fluidly connected to the fluid flow path 1040 through a connector 1052 to provide negative pressure to the wound site through the wound dressing 1006. The calibrated leak path 1026 is fluidly connected to an air leak 1012 to provide gas (e.g., air) from the air leak through the wound dressing 1006 to the wound. As shown in FIG. 10, the calibrated leak path 1026 and the suction path 1024 may be fluidly connected to each other only through the wound, as previously described in connection with FIGS. 9A-C. In some embodiments, the air leak 1012 may be disposed at any suitable location within the fluid flow path. For example, the air leak 1012 may be incorporated into the connector 1052. In some embodiments, the air leak may be electronically or electromechanically adjusted by a controller of the system to close or enlarge the leak. For example, the controller can communicate with the air leaks to open and close each air leak individually or as a unit. For example, the air leaks may be solenoid valves. The communication between the air leaks and the controller may be wired or wireless.

[0084] In some embodiments, the suction adapter 1020 can maintain a constant leak rate through the air leak 1012 while negative pressure is applied through a negative pressure source. Some embodiments can support an air leak of 1, 2, 3, 4, 5, 6, 7, 8, 9 mL / min or more (+ / - .5 mL / min or another suitable deviation). Some embodiments can support an air leak of 10, 20, 30, 40, 50, 60, 70, 80, 90 mL / min or more (+ / - several mL / min or another suitable deviation). Some embodiments can support an air leak of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 L / min or more (+ / - several centrifugal / min or another suitable deviation). In some instances, the leak rate may be discussed in terms of a controlled leak path (CLP), where the CLP is a suitable constant. For example, the air leak may have a leak rate of 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more. For example, assuming a leak rate of 0.1 L / min, 1 CLP may correspond to 0.1 L / min and 5 CLP may correspond to 0.5 L / min. If there is a stronger air leak, the negative pressure source must work harder because it will deplete the power source faster. Thus, in some embodiments, a relatively low leak rate is selected.

[0085] FIG. 15 illustrates an embodiment of a flexible suction adapter 1500 similar to the embodiment of flexible suction adapter 900 illustrated in and described in conjunction with FIGS. 9A-C. FIG. 15 illustrates a cross-sectional view of the suction adapter 1500. The suction adapter 1500 may include a bridge portion 1502 having a proximal end 1503 and a distal end 1505, and an applicator 1520 at the distal end 1505 of the bridge portion 1502 to form the flexible suction adapter 1500. The flexible suction adapter is preferably constructed in a manner similar to the flexible suction adapter 5500, the suction adapter 900, or any other suction adapter disclosed herein, and the bridge portion 1502 may be constructed from a similar double layer arrangement as previously described. For example, the bridge portion 1502 may include an upper channel spacer layer or material 1512 positioned between a top layer 1510 and a middle layer 1514 , and a lower channel spacer layer or material 1516 positioned between the middle layer 1514 and a bottom layer 1518 .

[0086] 15, a controlled gas leak 1524 (which may also be referred to as a gas leak, air leak, or controlled air leak) may be disposed on the bridge portion 1502, e.g., at a proximal end thereof. The air leak 1524 may include an opening or channel that extends through the top layer 1510 such that the air leak 1524 is in fluid communication with the top channel 1512. The gas leak 1524 may include a filter, such as the filter 925 of the flexible suction adapter 900 shown in and described in connection with FIGS. 9A-C.

[0087] The applicator 1520 preferably includes an attachment point for the bridge portion 1502 at the distal end 1505, such as, for example, using a section of double-sided adhesive tape. As will be appreciated, different attachment methods are also contemplated, such as, for example, heat sealing, welding, or a suitable adhesive.

[0088] The connector 1504 may be disposed at the proximal end 1503 of the bridge portion 1502 to connect to at least one of the channels 1512 and / or 1516. As shown in FIG. 15 , the channel connector 1506 may be provided at the proximal end 1503 of the bridge portion 1502. The channel connector 1506 may be configured to be embedded within the lower channel layer 1516 to form a secure fluid connection. With one end of the channel connector 1506 embedded in the lower channel layer 1516, the other end of the channel connector 1506 may connect or communicate with the connector 1504 or may be directly connected to a tube or lumen connected to a negative pressure source.

[0089] Each of the components of the suction adapter 1500 may be similar to the corresponding components of the suction adapter 5500 or the suction adapter 900, and therefore the description of each corresponding component of the suction adapter 1500 previously mentioned in this specification also applies to each component of the suction adapter 5500 or the suction adapter 900, except as described below.

[0090] In a manner similar to suction adapter 5500 and suction adapter 900, the upper fluid passageway may be defined by and between upper layer 1510 and middle layer 1514, and the lower fluid passageway may be defined by and between middle layer 1514 and lower layer 1518. In some cases, as shown in FIGS. 15-18 , upper layer 1510 and lower layer 1518 may extend further at distal end 1505 than middle layer 1514, such that upper layer 1510 and lower layer 1518 may be directly connected (e.g., sealed) to one another at distal end 1505. The upper fluid passageway may include an upper channel spacer material or layer 1512. The lower fluid passageway may include a lower channel spacer layer 1516.

[0091] In some cases, as illustrated in FIGS. 15-17, the top channel spacer layer 1512 may extend further at the distal end 1505 than the bottom channel spacer layer 1516 to support the top layer 1510. In some embodiments, as illustrated in FIGS. 15-17, the distal ends of layers 1510, 1514, and 1518, as well as the channel spacer layers 1512 and 1516, may be extended at their distal ends (located over the wound site) to form a "teardrop" or other extended shape. The bottom fluid passage may further include an open portion or hollow space 1570 below the distal end of the top channel spacer layer 1512. The hollow space 1570 may be positioned distally away from the distal end of the bottom channel spacer layer 1516. The hollow space 1570 may collapse due to negative pressure, as described in more detail elsewhere herein. The hollow space 1570 may be devoid of the bottom channel spacer material 1516. The hollow space 1570 may be empty or may include a void.

[0092] In some cases, as shown in FIGS. 15 and 16, the suction adapter 1500 can include at least one opening 1552 in the bottom layer 1518, for example, at an expanded distal end of the bottom layer 1518. The opening 1552 can be formed as a single hole or multiple smaller holes. As illustrated, the opening 1552 can be located on a central longitudinal axis of the bottom layer 1518, or the opening 1552 can be off the central longitudinal axis. The applicator 1520 can have an opening 1562 configured to align with the opening 1552. As shown in FIGS. 15 and 17, the middle layer 1514 can include an opening 1517, for example, at a distal end of the middle layer 1514. The opening 1517 can provide fluid communication between the upper and lower fluid channels. The opening 1517 can be in fluid communication with the hollow space 1570, such as being located above the hollow space 1570. The opening 1517 may be positioned distally away from the distal end of the lower channel spacer layer 1516. The lower channel spacer layer 1516 may terminate at a distal end away from the opening in the middle layer 1517. The distal end of the lower channel spacer layer 1516 may not overlap the opening 1517 in the middle layer 1514.

[0093] In some embodiments, the upper channel spacer material 1512 can be provided on and extend along a central longitudinal axis of the suction adapter 1500. The upper channel spacer material 1512 can extend distally of any portion of the lower channel spacer material 1516 that is on the central longitudinal axis. Thus, above at least one opening 1552 in the lower layer 1518, the upper channel spacer material 1512 can be the distally visible portion of the lower channel spacer material 1516.

[0094] 15, the opening 1552 may be positioned within the hollow space 1570. In this manner, the opening 1552 may be fluidly connected to an upper fluid channel with the upper channel spacer layer 1512, thereby forming a gas leak flow (e.g., air leak flow) extending distally from the air leak 1524 toward the wound through the opening 1517, the hollow space 1570, and the opening 1552. The opening 1552 may be fluidly connected via the hollow space 1570 to a lower fluid channel with the lower channel spacer layer 1516, thereby forming an aspiration flow and / or negative pressure source extending distally from the connector 1504.

[0095] In some cases, the top layer 1510 may form a fluid-tight seal with the middle layer 1514 and / or the bottom layer 1518, and the middle layer 1514 may form a fluid-tight seal with the top layer 1510 and the bottom layer 1518, such that the top fluid channel extends distally from the air leak 1524 to the opening 1552, but can be fluidly separated with the bottom fluid channel extending distally from the connector 1504 to the opening 1552, except at the distal end 1505. The top layer 1510, middle layer 1514, and bottom layer 1518 may be sealed to one another using any means described herein, for example, by melting, welding, or with an adhesive.

[0096] In some cases, the lower fluid channel may include a filter (not shown) adjacent the opening 1552. The filter may be configured to substantially prevent wound exudate from entering the lower fluid channel. The filter may be impermeable to liquids and may be permeable to gases and is provided to act as a liquid barrier and ensure that liquids cannot escape the wound dressing, such that a canister to collect wound fluid may not be required between the suction adapter and the negative pressure source. The filter may be hydrophobic. The filter may be attached or sealed to the suction adapter and / or cover film, on the wound dressing. For example, the filter may be molded into the suction adapter 1500 or may be adhered to the bottom layer 1518 of the suction adapter 1500 using an adhesive, such as a UV-curable adhesive.

[0097] Figure 18 illustrates a bottom view of the distal end 1505 of the suction adapter 1500. As shown in Figure 18, when viewed from the bottom, the lower channel layer 1516 and / or the middle layer 1514 may be at least partially exposed or visible through the opening 1552 and the opening 1562 in the applicator 1520. The opening 1552 can at least partially overlap with the opening 1562 in the applicator 1520.

[0098] In some cases, the opening 1517 and the opening 1552 are aligned such that the opening 1517 in the intermediate layer 1514 is at least partially exposed or visible through the openings 1552 and 1562. The opening 1517 can at least partially overlap the openings 1552 and 1562. A portion of the upper channel layer 1512 above the opening 1517 can be exposed to or overlap the openings 1552 and 1556. The openings 1552 and 1562 can have a similar or larger size than the opening 1517. The entire opening 1517 is above the openings 1552 and / or 1562, and the opening 1517 can completely overlap or be exposed through the openings 1552 and / or 1562. In some cases, the opening 1517 can partially overlap or be exposed through the openings 1552 and / or 1562. The center of opening 1517 can be positioned distally from the center of opening 1552 .

[0099] When negative pressure is applied to the suction adapter 1500, for example, through the connector 1504 and the lower channel layer 1516, the hollow space 1570 may collapse. Such collapse may terminate or prevent fluid communication between the lower fluid passage (e.g., the lower channel layer 1516) and the upper fluid passage (e.g., the upper channel layer 1512) through the hollow space 1570. In this manner, gas flow (e.g., air flow) through the upper fluid passage may not be directly transmitted to the lower fluid passage. Instead, when the suction adapter 1500 is positioned over an opening in a wound dressing positioned over a wound and negative pressure is applied to the suction adapter 1500 through the connector 1504, gas flow may be transmitted to the lower fluid passage through the openings 1517 and 1552, the openings in the wound dressing, and the wound filler positioned at the wound. Gas flow may be communicated to the lower fluid passage as a result of the lower channel layer portion 1564 communicating with one or more of the dressing or wound filler filled wound at the distal end of the lower channel spacer material 1516. As described herein, such an arrangement may advantageously provide a more accurate determination of blockage (e.g., when the suction adapter is not properly positioned on the wound) because the fluid flow path between the gas delivered through the upper fluid passage and the suction delivered through the lower fluid passage is provided only through the openings in the wound dressing and wound filler and not through the hollow space 1570.

[0100] As described herein, the hollow space 1570 may collapse due to the application of negative pressure. While the upper spacer layer 1512 and the lower spacer layer 1516 may collapse to a certain extent, the collapse of the hollow space 1570 may not occur to the other components of the suction adapter 1500 to a greater extent because there is no internal structure in the hollow space 1570 that would resist the collapse. When the hollow space 1570 collapses, the distal end of the middle layer 1514 above the hollow space 1570 may be drawn towards the opening 1552 in the lower layer 1518 such that the distal end of the middle layer 1514 blocks fluid flow between the upper and lower fluid passages. Thus, when the hollow space 1570 is collapsed, airflow may only be achieved between the upper and lower fluid passages through the openings in the wound dressing, as described herein. 19-21 show the suction adapter 1500 attached to a wound dressing 1900 positioned over a wound filled with wound filler. As shown in FIGS. 19-21, the distal end of the suction adapter 1500 collapses when negative pressure is applied.

[0101] The distal end of the lower channel spacer layer 1516 and the opening 1517 of the middle layer 1514 may be spaced apart sufficiently from one another such that the opening 1517 aligns with the opening 1552 to allow gas flow (e.g., air flow) from the upper fluid passageway to the wound when the middle layer 1514 is retracted into the opening 1552. For example, the distance between the distal end of the lower channel spacer layer 1516 and the center of the opening 1517 may be greater than or less than 5 mm, greater than or less than 1 cm, greater than or less than 2 cm, greater than or less than 3 cm, or greater than or less than 5 cm, etc. In some cases, as a result of the collapse of the hollow space 1570, when the middle layer 1514 is retracted towards the opening 1552, the entire opening 1517 is positioned above the opening 1552 or the opening 1562, thereby placing the entire opening 1517 in fluid communication with the opening of the wound dressing.

[0102] 18 , a portion of the lower fluid channel layer 1516 may be exposed at an opening 1552 in the lower layer 1518 or an opening 1556 in the applicator 1520. Such a portion may be a lower channel layer portion 1564. As described herein, fluid flow between the wound and the lower fluid channel may be maintained through the exposed portion of the lower fluid channel layer 1516 when negative pressure is applied and the distal end of the middle layer 1514 is drawn into the opening 1552.

[0103] In operation, the suction adapter 1500 provides a gas (e.g., air) leak path extending into the wound dressing that is fluidly separated from the suction flow path that extends from the wound dressing (e.g., via the upper fluid passage) to the negative pressure source (e.g., via the lower fluid passage). By having an air leak path that is fluidly separated from the suction flow path described herein, if the opening 1552 is blocked, the negative pressure source may stop drawing in gas (e.g., air) provided by the suction adapter because the gas leak will only flow through the wound, as described herein. This allows for detection of blockage of the suction adapter, for example, the suction adapter not being properly positioned over an opening formed in a wound cover that is placed over a wound or blockage by wound exudate. Additionally, by isolating the controlled air leak path, it may be easier to measure the flow or pressure through the suction flow path without interference from the air leak.

[0104] 22 and 23 illustrate bottom views of different embodiments of the distal end 1605, 1705 of the suction adapter 1600, 1700 similar to the embodiments of the flexible suction adapter 900, 1500 illustrated in and described in conjunction with FIGS. 9A-C and 15-18. Some of the different layers are shown as partially transparent to show the orientation of the different layers. Reference numbers of the same or substantially the same features may share the same last two digits. As shown in FIGS. 22 and 23, when viewed from the bottom, the middle layer 1614, 1714 may be at least partially exposed or visible through the opening 1652, 1752. At least one opening 1652, 1752 of the suction adapter 1600, 1700 may at least partially overlap with an opening 1662, 1762 of the applicator 1620, 1720.

[0105] As shown in FIG. 22, the distal end of the lower channel spacer layer 1616 may have a fork shape including a base portion 1616a and two protrusions or side portions 1616b, 1616c extending from the base portion 1616a. The two side portions 1616b, 1616c may extend from opposing sides of the base portion 1616a such that the two side portions 1616b, 1616c are spaced apart. This configuration may provide additional support to the suction adapter 1600 and prevent at least some wrinkling of the different layers (e.g., the bottom layer 1618). In some embodiments, the various openings 1617, 1652, 1662 may be positioned between the two side portions 1616b, 1616c, and the two side portions 1616b, 1616c may extend distally beyond the openings 1617, 1652, 1662. In some embodiments, the various openings 1617, 1652, 1662 may be positioned distal to the base portion 1616a.

[0106] 23 illustrates different embodiments of the suction adapter 1700 having differently shaped lower channel spacer layers 1716. In the illustrated configuration, the lower channel spacer layer 1716 includes an extended distal end 1716a. The extended distal end 1716a may have a straight distal edge that may be positioned adjacent a proximal portion of the opening 1752 of the suction adapter 1700 such that the extended distal end 1716a of the lower channel spacer layer 1716 does not overlap the opening 1752. In some configurations, the extended distal end 1716a of the lower channel spacer layer 1716 may at least partially overlap the opening 1752.

[0107] 24A-26B illustrate bottom views of different embodiments of the distal ends of middle layers 2014, 2114, 2214 and bottom layers 2018, 2118, 2218 that can be used with any of the suction adapters described herein. The middle layers 2014, 2114, 2214 and bottom layers 2018, 2118, 2218 can be similar to the embodiments illustrated in and described in connection with FIGS. 9A-C and 15-18. Reference numbers for the same or substantially the same features may share the same last three digits.

[0108] 24A and B illustrate an embodiment of the middle layer 2014 and the bottom layer 2018. As shown in FIG. 24A, the distal end of the middle layer 2014 can have a rectangular shape having a first length L1 measured from the distal edge 2015 of the middle layer 2014 and along the longitudinal axis of the middle layer 2014. The opening 2017 can be located at or near the center of the distal end of the middle layer 2014. For example, the center of the opening 2017 can be located a second length L2 from the distal edge 2015 and aligned with the longitudinal centerline of the middle layer 2014. The second length L2 can be about half of the first length L1. The opening 2017 can have an oval-like shape including a third length L3 and a width W1. In some embodiments, the third length L3 can be about 5 mm to about 20 mm, about 10 mm to about 15 mm, or about 10 mm. In some embodiments, the width W3 can be between about 2 mm and about 10 mm, between about 5 mm and about 7 mm, or about 4 mm.

[0109] As shown in FIG. 24B, the distal end of the bottom layer 2018 may have a rectangular shape having a first length L4 measured from the distal edge 2019 of the bottom layer 2018 and along the longitudinal axis of the bottom layer 2018. The opening 2052 may be located at or near the center of the distal end of the bottom layer 2018. For example, the center of the opening 2052 may be located a second length L5 from the distal edge 2019 and aligned with the longitudinal centerline of the bottom layer 2018. The second length L5 may be about half of the first length L4. The opening 2052 may have a circular shape including a diameter D1. In some embodiments, the diameter D1 may be about 10 mm to about 40 mm, about 20 mm to about 30 mm, or about 16 mm.

[0110] 25A and B illustrate an embodiment of the middle layer 2114 and the bottom layer 2118. As shown in FIG. 25A, the distal end of the middle layer 2114 may have a rectangular shape having a first length L6 measured from the distal edge 2115 of the middle layer 2114 and along the longitudinal axis of the middle layer 2114. The opening 2117 may be located at or near the center of the distal end of the middle layer 2114. For example, the center of the opening 2117 may be located a second length L7 from the distal edge 2115 and aligned with the longitudinal centerline of the middle layer 2114. The second length L7 may be about half of the first length L6. The opening 2117 may have an oval-like shape including a third length L8 and a width W2. In some embodiments, the third length L8 may be about 5 mm to about 20 mm, about 10 mm to about 15 mm, or about 10 mm. In some embodiments, the width W2 can be from about 2 mm to about 10 mm, from about 5 mm to about 7 mm, or about 4 mm.

[0111] 25B, the distal end of the bottom layer 2118 can have a rectangular shape having a first length L9 measured from the distal edge 2119 of the bottom layer 2118 and along the longitudinal axis of the bottom layer 2118. The opening 2152 can be located at or near the center of the distal end of the bottom layer 2118. For example, the center of the opening 2152 can be located a second length L9 from the distal edge 2119. 10 and may be aligned with a longitudinal centerline of the bottom layer 2118. The second length L5 may be about half of the first length L4. The opening 2152 may have a circular shape with a diameter D2. In some embodiments, the diameter D2 may be about 10 mm to about 40 mm, about 20 mm to about 30 mm, or about 20 mm.

[0112] 26A and B illustrate an embodiment of the middle layer 2214 and the bottom layer 2218. As shown in FIG. 26A, the distal end of the middle layer 2214 has a first length L measured from the distal edge 2215 of the middle layer 2214 and along the longitudinal axis of the middle layer 2214. 11 The opening 2217 may have a rectangular shape having a second length L from the distal edge 2215. The opening 2217 may be located at or near the center of the distal end of the middle layer 2214. For example, the center of the opening 2217 may be located at or near the second length L from the distal edge 2215. 12 and may be aligned with the longitudinal centerline of the middle layer 2214. 12 is the first length L 11 The opening 2217 may be approximately half of the third length L 13 and width W3. In some embodiments, the third length L 13 In some embodiments, the width W3 can be about 2 mm to about 10 mm, about 5 mm to about 7 mm, or about 4 mm.

[0113] As shown in FIG. 26B, the distal end of the bottom layer 2218 has a first length L measured from a distal edge 2219 of the bottom layer 2218 and along a longitudinal axis of the bottom layer 2218. 14The opening 2252 may have a rectangular shape having a second length L from the distal edge 2219. The opening 2252 may be located at or near the center of the distal end of the bottom layer 2218. For example, the center of the opening 2252 may be located a distance of a second length L from the distal edge 2219. 15 and may be aligned with the longitudinal centerline of the bottom layer 2218. 15 is the first length L 14 The opening 2252 may have a circular shape with a diameter D3. In some embodiments, the diameter D3 may be between about 10 mm and about 50 mm, between about 20 mm and about 40 mm, or about 30 mm.

[0114] FIG. 27 illustrates an embodiment of a flexible suction adapter 2300 similar to the embodiments of the flexible suction adapters 900, 1500 illustrated in and described in conjunction with FIGS. 9A-C, and 15-18. Reference numbers of the same or substantially the same features may share the same last two digits. As shown in FIG. 27, the distal end 2305 of the suction adapter 2300 may include a welded portion 2319 where a portion of the bottom layer 2318 may be welded to the middle layer 2314. The welded portion 2319 may be positioned at at least one opening of the suction adapter 2300 such that the at least one opening includes a proximal opening 2352a spaced from a distal opening 2352b.

[0115] In some embodiments, the welded portion 2319 may terminate or prevent fluid communication between the lower fluid passage (e.g., lower channel layer 2316) and the upper fluid passage (e.g., upper channel layer 2312) through the hollow space 2370. In this manner, gas flow (e.g., air flow) through the upper fluid passage may not be directly transmitted to the lower fluid passage. Instead, when the suction adapter 2300 is positioned over an opening in a wound dressing positioned over the wound 2330 and negative pressure is applied to the suction adapter 2300 through the connector 2304, gas flow may be transmitted to the lower fluid passage through the openings 2317, 2352a and 2352b, the openings in the wound dressing, and the wound filler positioned at the wound 2330. Gas flow may be communicated to the lower fluid passage as a result of the lower channel layer portion 2364 at the distal end of the lower channel spacer material 2316 communicating with one or more of the dressing or wound filler filled wounds 2330. As described herein, such an arrangement may advantageously provide a more accurate determination of occlusion (e.g., when the suction adapter 2300 is not properly positioned on the wound 2330) since the fluid flow path between the gas delivered through the upper fluid passage and the suction delivered through the lower fluid passage is provided only through the openings in the wound dressing and wound filler and not through the hollow space 2370.

[0116] 28A-30B illustrate bottom views of different embodiments of the distal ends of middle layers 2414, 2514, 2614 and bottom layers 2418, 2518, 2618 that can be used with suction adapter 2300 described above or any suction adapter described herein. Middle layers 2414, 2514, 2614 and bottom layers 2418, 2518, 2618 can be similar to the embodiments illustrated in and described in connection with FIGS. 9A-C and 15-18 and 27. Reference numbers for the same or substantially the same features may share the same last three digits.

[0117] 28A and B illustrate an embodiment of a middle layer 2414 and a bottom layer 2418. As shown in FIG. 28A, the distal end of the middle layer 2414 has a first length L measured from a distal edge 2415 of the middle layer 2414 along a longitudinal axis of the middle layer 2414. 16 The opening 2417 may have a rectangular shape having a second length L from the distal edge 2415. The opening 2417 may be located at or near the center of the distal end of the middle layer 2414. For example, the center of the opening 2417 may be located at or near the second length L from the distal edge 2415. 17 and may be aligned with the longitudinal centerline of the intermediate layer 2414. 17 is the first length L 16 The opening 2417 may be approximately half of the third length L 18 and width W4. In some embodiments, the third length L 18 In some embodiments, the width W4 can be about 2 mm to about 10 mm, about 5 mm to about 7 mm, or about 4 mm.

[0118] As shown in FIG. 28B , the distal end of the bottom layer 2418 has a first length L measured from a distal edge 2419 of the bottom layer 2418 and along a longitudinal axis of the bottom layer 2418. 19 The openings 2452a, 2452b can be positioned at or near the center of the distal end of the bottom layer 2418. For example, the center of the welded portion 2419 between the two openings 2452a, 2452b is located a distance of the second length L from the distal edge 2419. 20 and may be aligned with the longitudinal centerline of the bottom layer 2418. 20 is the first length L 19The welded portion 2419 may have a width W5 separating the two openings 2452a, 2452b. The width W5 may be about 1 mm to about 10 mm, about 3 mm to about 8 mm, or about 6 mm. The openings 2452a, 2452b may each have a semicircular shape including a diameter D4 measured from an edge of the proximal opening 2452a, through the welded portion 2419, to an edge of the distal opening 2452b. In some embodiments, the diameter D4 may be about 10 mm to about 50 mm, about 20 mm to about 40 mm, or about 30 mm.

[0119] 29A and B illustrate an embodiment of a middle layer 2514 and a bottom layer 2518. As shown in FIG. 29A and B, the middle layer 2514 and the bottom layer 2518 may be the same as or similar to the middle layer 2414 and the bottom layer 2518 described above in connection with FIG. 28A-B. As shown in FIG. 29B, the welded portion 2519 may have a width W6 separating the two openings 2552a, 2552b. The width W6 may be about 1 mm to about 10 mm, about 3 mm to about 8 mm, or about 4 mm. The openings 2552a, 2552b may each have a semicircular shape including a diameter D5 measured from an edge of the proximal opening 2552a, through the welded portion 2519, to an edge of the distal opening 2552b. In some embodiments, the diameter D5 may be about 10 mm to about 50 mm, about 20 mm to about 40 mm, or about 20 mm.

[0120] 30A and B illustrate an embodiment of the middle layer 2614 and the bottom layer 2618. As shown in FIG. 30A and B, the middle layer 2614 and the bottom layer 2618 may be the same as or similar to the middle layer 2414 and the bottom layer 2518 described above in connection with FIG. 28A and B. As shown in FIG. 30B, the proximal opening 2652a and the distal opening 2652b may be positioned at or near the center of the distal end of the bottom layer 2618. For example, the center of the welded portion 2619 between the two openings 2652a, 2652b may be aligned with the longitudinal centerline of the bottom layer 2618. Additionally, the center of the welded portion 2619 may be located at a distance of a length L from the distal edge 2619. 20The weld portion 2619 may be offset from the center of the distal end of the bottom layer 2618 located at the center of the weld portion 2619. The weld portion 2619 may have a width W7 that separates the two openings 2652a, 2652b. The width W7 may be about 5 mm to about 20 mm, about 10 mm to about 15 mm, or about 10 mm.

[0121] Multiple dressing negative wound treatment 11A and 11B illustrate a negative pressure wound treatment system 400 according to some embodiments. The systems 400a, 400b (collectively 400) may include a negative pressure source, such as a pump assembly or negative pressure unit 434. In some embodiments, the negative pressure unit 434 is the same as that illustrated in FIG. 2. The negative pressure unit 434 may be fluidly connected to one or more wound dressings 406a, 406b (collectively referred to as 406) to provide negative pressure to one or more wounds. In some embodiments, the fluid connection between the wound dressings 406 and the negative pressure unit 434 is referred to as a fluid flow path (e.g., a path through which fluid is drawn from the wound via a negative pressure flow). For example, a first fluid flow path may include a component that provides a fluid connection from the negative pressure unit 434 to the first wound dressing 406a. As a non-limiting example, the first fluid flow path may include a path from wound dressing 406a to negative pressure unit 434 or a path from first wound dressing 406a to an inlet of bifurcated fitting 444 in fluid connection with negative pressure unit 434. As illustrated, system 400 may include multiple wound dressings (and corresponding fluid flow paths) in fluid connection with negative pressure unit 434 via multiple suction adapters, such as suction adapter 900 described in connection with FIGS. 9A-C and / or suction adapter 1020 described in connection with FIG. 10. Thus, the description of suction adapters 900 and 1020 and their components herein may also apply to the suction adapters and components thereof of systems 400a and 400b. For example, the suction adapters for systems 400a and 400b may include a controlled leak channel that is fluidly isolated from the suction channel. Each wound dressing and fluid flow path may include various features or elements that match or resemble features or elements of another wound dressing or fluid flow path in the system. For ease of reference, one or more corresponding features or elements may be collectively referred to using a reference number without a corresponding letter. For example, bridge 402a and bridge 402b may be collectively referred to as bridge 402. However, it should be noted that in some embodiments, the collectively referred to elements may not be identical and may have different features or attributes.

[0122] 11A, the system 400a may include a bridge 402 having a proximal end 403 and a distal end 405 and a suction adapter, such as suction adapter 900 or 1020, including an applicator 420 at the distal end 405 of the bridge 402 to form a flexible suction interface or adapter. The negative pressure unit 434 may include a canister or other container for storing wound exudate and other fluids that may be removed from the wound. The negative pressure unit 434 may be the negative pressure unit 5534 described in connection with FIG. 2. Alternatively, or additionally, the wound dressing 406 may collect wound exudate and other fluids and there may be no canister. In some embodiments, multiple canisters are provided, for example, one canister per wound dressing. In some embodiments, the negative pressure unit 434 may be a Renasys touch device manufactured by Smith & Nephew. In some embodiments, connectors other than the Renasys Softport or devices other than the Renasys Touch may be used.

[0123] FIG. 11B illustrates the embodiment of FIG. 11A with a flexible suction adapter placed over the wound. In some embodiments, the applicator 420 is placed over an opening 435 formed in a drape 431, which is placed over a suitably prepared wound 430, which may be filled with a wound packing material such as foam or gauze. The negative pressure unit 434 is then activated by the negative pressure unit 434, which is connected to the connector 404 via a tube 440 or an inlet manifold branch attachment or connector 444, thereby providing negative pressure to the wound via the fluid flow path. The application of negative pressure may be performed until a desired level of healing of the wound 430 is achieved. Although two wounds and wound dressings are illustrated in FIGS. 11A and 11B, in some embodiments, the negative pressure unit 434 may provide treatment to more than one wound. In some implementations, negative pressure wound treatment may be provided to a single wound.

[0124] Mounting Part The negative pressure unit 434 may be in fluid communication with the wound dressing 406 via one or more tubes 440, 442, one or more bridges 402, or via an inlet manifold branch fitting 444. For example, the negative pressure unit 434 may be in fluid communication with multiple wound dressings 406 via tubes 440, inlet manifold branch fitting 444, tubes 442, and bridges 402. As another example, the manifold branch fitting 444 may be directly connected to the negative pressure unit 434 without the use of tubes 440. As shown in FIGS. 11A and 11B, the inlet manifold branch fitting 444 may be configured to connect the negative pressure unit 434 to multiple fluid flow paths via multiple dressing conduit fittings 445a, 445b. The inlet manifold branch fitting 444 may include any number of dressing conduit fittings 445 configured to be fluidly connected to the negative pressure fitting 446 via junctions. For example, the inlet manifold branch fitting can include two cladding conduit fittings 445a, 445b, three cladding conduit fittings, or more than two cladding tube fittings.

[0125] The multiple dressing conduit mounting portions 445 may include a first dressing conduit mounting portion 445a and a second dressing conduit mounting portion 445b. However, it may be understood that more or fewer dressing conduit mounting portions may be included in the inlet manifold branch mounting portion 444. Each of the dressing conduit mounting portions 445 includes a shaft extending away from a junction and including an inlet distal to the junction. The inlet is configured to fluidly connect at least a portion of the fluid flow path to the negative pressure unit 434.

[0126] The inlet manifold branch fitting 444 may also include one or more negative pressure fittings 446. Each of the negative pressure fittings 446 may include a shaft extending away from the junction and an inlet distal to the junction. The inlet(s) may be configured to fluidly connect to the negative pressure unit 434. For example, the inlets may include male or female non-luer connectors that attach to corresponding male or female connectors of a conduit or pump. In some embodiments, the negative pressure fittings 446 are attached to the negative pressure unit 434 via tubing 440 or other conduit. The negative pressure fittings 446 may also be directly attached to (or integral with) the housing of the negative pressure unit 434.

[0127] The inlet manifold branch fitting 444 or conduit may include one or more valves, clamps, caps, air leaks, or other flow control mechanisms built in that may be configured to admit fluid into the fluid flow path or, alternatively, block or restrict the flow of fluid or fluid passage. In some embodiments, the valves, air leaks, or other flow control mechanisms of the inlet manifold branch fitting 444 may be electronically opened or closed. For example, a controller of the negative pressure unit 434 may be in communication with the valves, air leaks, etc. to open or close each individually or as a unit. This communication may be wired or wireless.

[0128] The dressing conduit attachment portion 445 may include a shaft that forms the top of a Y- (two wound), W- (three wound), or other shape of inlet manifold branch attachment. The proximal end of the dressing conduit shaft and the distal end of the pump conduit shaft may meet at a junction. In some embodiments, the junction may include a hinge that allows rotation of the shaft about the junction. In some embodiments, the inlet manifold branch attachment may be a W-shaped connector (as illustrated in FIG. 6). In such an embodiment, the inlet manifold branch attachment may include three dressing conduit attachment portions and one negative pressure attachment portion.

[0129] The inlet manifold branch fitting may comprise hard plastic or soft plastic tubing, or alternatively may be encapsulated in a soft silicone sleeve to enhance patient comfort and prevent the inlet manifold branch fitting 444 from becoming a pressure point.

[0130] In some embodiments, utilizing an inlet manifold bifurcation attachment, the negative pressure unit can be attached to multiple wound dressings 406, allowing the negative pressure unit to simultaneously draw fluid from multiple wounds 430. The performance and wound healing capabilities (e.g., fluid management) of such a system can match or exceed the performance and wound healing capabilities of a standard single wound dressing with a single pump setup.

[0131] In some embodiments, an integrated inlet manifold (not shown) can be used in place of the inlet manifold bifurcated fitting 444. In such examples, the inlet manifold can be integrated into (e.g., directly attached to) the negative pressure unit 434 or the pump housing such that one or more fluid flow paths can be fluidly connected to the pump via one or more inlets of the integrated inlet manifold. The integrated inlet manifold may include a split fitting (similar to the Y-shaped or W-shaped bifurcated fittings described herein) or may include one or more separately integrated inlets in fluid connection with the pump.

[0132] Determining operating conditions In some embodiments, the system 400 can apply negative pressure to one or more wounds. The level of negative pressure in the one or more wounds (e.g., under one or more wound dressings) can be sufficiently close to the level of negative pressure in the negative pressure source. For example, an acceptable level of pressure maintained at the wound can be ±1 mmHg, ±5 mmHg, ±10 mmHg, ±25 mmHg, and the like, of the negative pressure set point. In some embodiments, the pressure can be maintained at this level within 95% (or another suitable percentage) of the time that the system 400 applies negative pressure. In some embodiments, an acceptable pressure level can include a pressure range between -40 to -120 mmHg. However, other pressure levels may be used as described herein.

[0133] As described in more detail herein, one or more air leaks, such as air leaks 424, 5524, 924, or 1012, in one or more fluid flow paths may be utilized to determine one or more operating conditions in the system. For example, the air leak may be a controlled air leak that allows a relatively constant flow of air, gas, or other fluid into the fluid flow path. In some embodiments, the flow from the air leak into the fluid flow path does not increase significantly when additional negative pressure is applied to the system. However, the presence of an air leak in the system may maintain a substantially constant baseline flow through the system when a steady state is achieved (e.g., a negative pressure set point is reached). The presence of an air leak may then require the negative pressure source to work harder to maintain a desired level of negative pressure at the wound(s). Thus, the system may determine the presence of one or more operating conditions (blockage, leak, full canister, misaligned suction adapter, etc.) by monitoring the flow through the fluid flow path(s), which may be measured directly or indirectly based on, for example, monitoring the activity of the negative pressure source.

[0134] In some embodiments, each fluid flow path may include an air leak (as illustrated in FIGS. 11A and 11B), and each air leak in a respective fluid flow path may allow a different air, gas, or other fluid flow rate into the system. In other words, each air leak in the system may have a different leak rate. For example, the leak rate of an air leak may be based at least in part on the size or shape of the air leak, whether the air leak includes a filter, the size or porosity level or level of obstruction of the filter, air leak, or filter, etc. Fluid entering a fluid flow path increases the flow rate of that fluid flow path.

[0135] Thus, each fluid flow path of the system 400 may have a different flow rate. The total flow rate (TFR) of the system 400 (e.g., the aggregate of the flow to each wound dressing) may be monitored, calculated, or determined and then used to determine an operating state of the system 400. The operating states may include, for example, a "no flow" state (e.g., all flow paths are blocked), a blocked state of one or more flow paths (e.g., a blocked state exists in a first fluid flow path and a blocked state exists in a second fluid flow path, etc.), a full canister state, normal operation (e.g., no blockage exists in any of the fluid flow paths), etc.

[0136] In some embodiments, the system 400 can provide an indication, such as an alarm, to inform a patient or caregiver of the operating status of the system 400 based on a comparison of the determined total flow rate and one or more flow thresholds. In some embodiments, the flow thresholds corresponding to the operating conditions of the system 400 are pre-determined. In some embodiments, the flow thresholds are based at least in part on dynamic measurements or calculations of the system 400, such as flow rate or pressure, during a particular mode of the system (e.g., a calibration mode).

[0137] 12 illustrates a diagram of a system for applying negative pressure according to some embodiments. As illustrated, the system 500 includes a negative pressure source 522 in fluid communication with the wound dressings 506a, 506b via a fluid flow path 540d, an inlet manifold branch fitting 544, and fluid flow paths 540a, 540b to apply negative pressure to one or more wound sites via suction paths 528a and 528b connected with the fluid flow paths 540a and 540b, respectively. The suction path 528a may be connected to the flow channel 540a at a connector 530, and the suction path 528b may be connected to the flow groove 540b at a connector 530. Each of the first fluid flow path 540a and the second fluid flow path 540b includes an air leak 512, 514 configured to admit fluid into the controlled air leak paths 526a and 526b, respectively. The controlled air leak paths 526a and 526b may be fluidly isolated from the suction channels 528a and 528b such that the controlled air leak paths and the suction paths are fluidly connected only through the wound bed.

[0138] In some embodiments, the air leaks can be electronically or electromechanically adjusted by a controller of the system to close or enlarge the leak. For example, the controller can communicate with the air leaks to open or close each air leak individually or as a unit. For example, the air leaks can be solenoid valves. The communication between the air leaks and the controller can be wired or wireless.

[0139] In some embodiments, the system 500 or 1000 can maintain a constant leak rate through the air leak while negative pressure is applied through the negative pressure source. Some embodiments can support an air leak of 1, 2, 3, 4, 5, 6, 7, 8, 9 mL / min or more (+ / - .5 mL / min or another suitable deviation). Some embodiments can support an air leak of 10, 20, 30, 40, 50, 60, 70, 80, 90 mL / min or more (+ / - several mL / min or another suitable deviation). Some embodiments can support an air leak of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 L / min or more (+ / - several centrifugal / min or another suitable deviation). In some instances, the leak rate may be discussed in terms of a controlled leak path (CLP), where the CLP is a suitable constant. For example, the air leak may have a leak rate of 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more. For example, assuming a leak rate of 0.1 L / min, 1 CLP may correspond to 0.1 L / min and 5 CLP may correspond to 0.5 L / min. If there is a stronger air leak, the negative pressure source must work harder because it will deplete the power source faster. Thus, in some embodiments, a relatively low leak rate is selected.

[0140] In some embodiments, the first air leak 512 has a different leak rate that is different from the second air leak 514. For example, the first air leak may have a leak rate of 1 CLP and the second air leak may have a leak rate of 2 CLP. Alternatively, the first air leak may have a leak rate of 0.5 CLP and the second leak may have a leak rate of 1 CLP. However, it should be noted that the leak rate of the system may be any suitable flow rate. Due to the different leak rates, the first and second fluid flow paths 520a, 520b may have different flow rates. Alternatively, the first air leak 512 and the second air leak 514 may be equal or approximately equal (e.g., + / - 0.1 L / min or another suitable deviation). For example, the first air leak 512 and the second air leak 514 may each have a leak rate of 1 CLP. However, it should be noted that the leak rate of the system may be any suitable flow rate. For equal leak rates, the first fluid flow path 520a and the second fluid flow path 520b may have similar flow rates. In some embodiments, the total flow rate (TFR) of the system is the sum of the flows coming from one or more wound dressings of the system. Thus, in some instances, the TFR may be equal to the flow rate of the fluid flow path 520d.

[0141] flow monitoring The system 500 or 1000 may monitor or determine the TFR in the system, for example, based on monitoring activity of the negative pressure source 522 or 1022. In certain embodiments, flow rate monitoring may be performed by a pump control processor (such as pump control processor 370 of FIG. 3) alone or in combination with a processor (such as user interface processor 310 of FIG. 3). Flow rate monitoring may be used, among other things, to ensure that treatment is properly delivered to one or more wounds, to detect blockages, full canister conditions, no flow conditions, or leaks, high pressures in one or more fluid flow paths, and to ensure that the flow rate is not dangerous (e.g., dangerously high).

[0142] In certain implementations, the system performs direct flow monitoring, for example, using one or more flow meters positioned in the fluid flow path. In some embodiments, the system performs indirect flow monitoring by measuring or monitoring activity of the negative pressure source, such as by monitoring activity of an actuator. For example, the system may monitor activity of the vacuum pump motor, including monitoring the speed of the vacuum pump motor using a tachometer, monitoring the current or voltage supplied to the pump (such as the current or voltage of a PWM signal), and the like. The system may continuously monitor one or more of these characteristics to determine activity of the negative pressure source.

[0143] In some embodiments, a tachometer (such as a Hall effect sensor) can be used to measure the activity level of the pump motor. The tachometer can be read periodically, such as every 100 milliseconds or another suitable period, and periodic readings taken over a period, such as 32 seconds or another suitable period, can be combined (e.g., averaged). The combined tachometer readings can be used to determine a flow rate, which can then be used for leak detection, occlusion detection, limiting maximum flow rates, and the like. The combined tachometer readings (e.g., counts or pulses) can be converted to a flow rate (e.g., mL / min) using one or more conversion equations or tables such that the TFR of the system (e.g., the sum of the flows in each fluid flow path associated with the wound dressing) is determined. In some embodiments, the TFR is determined according to the following equation: TFR=C1*F*P+C2 where TFR is the total flow rate, F is the frequency of the pump tachometer signal, P is the pressure generated by the pump (e.g., the negative pressure set point), and C1 and C2 are suitable constants (determined for a given negative pressure source). The determined flow rate can be compared to various flow rate thresholds, such as one or more occlusion thresholds, to determine the presence of a particular condition, such as an occlusion, a leak, a full canister, etc.

[0144] In some embodiments, a total flow rate of the system can be determined. The TFR can correspond to the sum of the leak rates seen by the negative pressure sources. For example, the expected TFR can be determined using, for example, one or more conversion equations or tables, e.g., in a calibration mode. The expected TFR can correspond to the TFR of the system in steady state operation (e.g., when the negative pressure set point is reached), in the absence of air leaks, etc. The system can then monitor the TFR and compare it to one or more leak or flow thresholds to determine the presence of a particular condition, such as a blockage, no flow, normal operation, a full canister, etc. In some implementations, the expected TFR can be determined at a non-steady state. In certain cases, multiple expected TFRs can be utilized.

[0145] In some embodiments, an occlusion condition is detected when the determined flow rate does not meet one or more flow thresholds. For example, if the occlusion condition exists for a certain amount of time, such as 30 seconds or another suitable amount of time, an occlusion alarm can be enabled. This approach can implement hysteresis so that the system does not falsely report the presence of one or more operating conditions. In embodiments where the system includes multiple wound dressings, a different occlusion alarm can be enabled for each wound dressing. If the determined flow rate exceeds one or more flow rate thresholds, the occlusion alarm can be disabled. In some embodiments, the system can distinguish between an occlusion in one or more fluid flow paths and a canister full condition.

[0146] In some embodiments, blockages and the presence of fluid in one or more fluid flow paths are detected by processing data from one or more pressure sensors (not shown), which may be positioned at any suitable location in the flow path. In some embodiments, the pressure sensor is positioned at or near the inlet of the negative pressure source. This detection can be enhanced by changing one or more settings of the pump, such as increasing the pressure level delivered by the pump, decreasing the pressure level, stopping the pump, changing the pump speed, changing the pump cadence, etc.

[0147] In some embodiments, the flow rate may be estimated as the volume of air, gas, or other fluid moving through the fluid flow path per unit time, normalized to standard temperature and pressure (e.g., 1 atmosphere). The flow rate may be calculated periodically, such as every 250 milliseconds or any other suitable time value, according to the following formula: TFR=Slope*Tachometer+Intercept

[0148] Tachometer is a short tachometer average (e.g., an average of the most recent tachometer readings, e.g., 2.5 seconds or another suitable time, measured in Hz), and Slope and Intercept are constants based on the negative pressure set point. Values ​​for Slope and Intercept can be determined for possible pressure set points of a given negative pressure source (e.g., -25mmHg, -40mmHg, -50mmHg, -60mmHg, -70mmHg, -80mmHg, -90mmHg, -100mmHg, -120mmHg, -140mmHg, -160mmHg, -180mmHg, -200mmHg). The flow rate as a function of pump speed may not be optimal as a single line, since pumps can be designed to be more efficient at lower flow rates. Thus, slope and intercept values ​​may be pre-calculated for various set points and various pumps. As described herein, the determined flow rate can be compared to various flow thresholds to determine the presence of certain operating conditions, such as a blocked condition, a no flow condition, a canister full condition, an abnormal condition, a normal condition, etc.

[0149] Additionally, the system can determine and monitor pressure within the fluid flow path using one or more sensors. For example, the fluid flow path can include a pressure sensor at or near the inlet manifold branch attachment 444, or anywhere else on the fluid flow path, at or near the wound dressing 406. In some embodiments, the pump assembly includes a pressure sensor at or near the inlet (or canister connection) of the pump assembly. This pressure sensor can measure the pressure within the canister (or within or near the dressing for canisterless systems). The pump assembly can continuously measure the pressure within the canister, such as every millisecond or any other suitable duration. A suitable number of recent pressure sensor measurements can be averaged to mitigate the effect of one or more erroneous measurements.

[0150] Based on the determined total flow rate, the pump assembly can monitor and detect various operating conditions described herein. One or more of these conditions can be detected, for example, by the flowcharts 700 or 800 illustrated in FIGS. 13 and 14. A blockage in one or more fluid flow paths can be determined by comparing the total flow rate to one or more flow thresholds. The comparison can be performed hysteresis, which is performed continuously or substantially continuously over or during a period of time, such as, for example, two minutes or any other suitable period of time. The one or more flow thresholds can be selected or determined based on a particular pressure set point, since the expected TFR can also depend on the set point. That is, to detect a blockage, the pump assembly can utilize multiple flow thresholds corresponding to a particular pressure set point. Alternatively, or additionally, the flow thresholds can be selected or determined based on the leak rate of one or more air leaks. As described herein, the flow rate can be indirectly determined by detecting and monitoring the pump speed.

[0151] If one or more flow thresholds are met or not met (e.g., over a period of time), the system determines that there is an occlusion in at least one of the fluid flow paths and provides an indication, which may include activating an alarm (e.g., visual, audio, or tactile), ceasing operation of the negative pressure, or the like. For example, to determine the presence of an occlusion, the pump assembly may determine whether the total flow rate meets, exceeds, or falls below the flow threshold for a two minute period, or any other suitable period of time. Since the total flow rate may be updated at regular time intervals due to regular sampling of the tachometer, the pump assembly may compare the updated total flow rate over the two minute period to the flow threshold. A blockage may be detected provided that each determined total flow rate during the two minute interval meets, exceeds, or falls below the flow threshold. Alternatively or additionally, a blockage may be detected if a majority of the calculated total flow rates, such as 9 out of 10 or any other suitable number, meets, exceeds, or falls below the flow threshold. A detected occlusion may be cleared when the total flow rate falls below (or exceeds) one or more flow thresholds for a period of time, such as 5 seconds or any other suitable period of time.

[0152] The threshold value may be any suitable flow threshold value, such as a value selected or determined based on the negative pressure set point and the expected flow rate in the fluid flow path, which may be determined as described herein.

[0153] In some embodiments, one or more flow sensors or flow meters can be used to directly measure fluid flow. In some embodiments, the pump assembly can utilize one or more of the techniques described herein in parallel to control the pump and detect various conditions. The pump assembly can be configured to arbitrate appropriately between usage parameters determined by different techniques. For example, the pump assembly can arbitrate between flow rates determined indirectly, such as based on pump speed measured by a tachometer, and directly, such as by using a flow meter. In certain embodiments, the pump assembly can determine the flow rate indirectly and utilize it to steer the flow rate determination as needed, such as when the indirectly determined flow rate is perceived to be inaccurate or unreliable.

[0154] In some embodiments, selecting or activating the Y- or W-connection feature for the treatment of multiple wounds can change or modify the detection of one or more operating conditions, such as an occlusion, a leak, a canister full condition, etc. Activation of the Y- or W-connection feature can adjust one or more of the various thresholds described herein. In some embodiments, the system automatically detects that a Y- or W-connector is present. For example, if a single wound dressing with a leak rate of 1 CLP is connected, the system can automatically detect that a Y-connector is present by detecting a leak higher than the expected leak of 1 CLP. For example, the system may prompt the user to confirm that another flow path is present, for example, with a leak rate of 2 CLP. If the user confirms, the system knows to detect an occlusion and can determine a flow threshold based at least in part on the determination of the leak rate. A similar determination can be used for a W-connector with three flow paths. For example, continuing with the previous example, if the system detects a leak higher than the expected leak of 3 CLP, the system can detect that a W-connector is present and can prompt the user to confirm that another flow path is present, for example, with a leak rate of 4 CLP. In some embodiments, a similar approach can be utilized when three or more wounds are being treated.

[0155] 13 shows a flow diagram of a process 700 for determining and indicating one or more operating conditions, according to some embodiments. In some embodiments, the process 700 is performed by the reduced pressure wound treatment system 500, such as by one or more controllers of the system.

[0156] At block 702, the process 700 determines one or more operating parameters. For example, the process 700 may determine the number of wound dressings attached, whether the fluid flow paths corresponding to the attached wound dressings include air leaks, leak rates of one or more air leaks, an expected total flow rate (TFR) of the system, an expected flow rate of each of the fluid flow paths, one or more flow thresholds, and an activity level of the negative pressure source, etc. In some embodiments, the process 600 may perform one or more of such determinations in a calibration mode. Alternatively, some or all of these determinations may be automatically detected or received by the process upon application of each wound dressing. In some embodiments, a user may input some or all of the operating parameters, or the process may perform internal calculations or utilize conversion equations or tables.

[0157] As described herein, in some embodiments, the process 700 can detect the presence of one or more attached wound dressings by detecting a higher than expected leak rate. For example, the process can automatically detect the presence of a Y-connector by detecting a leak higher than expected leak rate and prompt the user to confirm that another flow path is present. If the user confirms, the process can determine how to detect the blockage. In other embodiments, the process can detect when a wound dressing is attached and can know the specification as an air leak section based on the attached wound dressing.

[0158] The process 700 can also determine an expected flow rate for each of the fluid flow paths corresponding to each of the attached wound dressings. As described herein, each of the fluid flow paths can include one or more air leaks that can be configured to receive fluid into the fluid flow path in which the air leak is located. Additionally, each of the air leaks can have a different leak rate (e.g., the rate at which fluid enters the fluid flow path). Thus, each of the fluid flow paths can have a different expected flow rate.

[0159] Based at least in part on the number or leak rate of the wound dressings of the one or more air leaks, the process 700 can determine a number of flow thresholds. For example, the process may have two wound dressings, each with a different flow rate. The process can determine that a first flow threshold corresponds to a flow rate equal to the sum of the expected flow rate of the first fluid flow path and the expected flow rate of the second fluid flow path. The second flow threshold corresponds to the expected flow rate of the second fluid flow path. The third flow threshold corresponds to the expected flow rate of the first fluid flow path. Thus, if the monitored TFR meets the first flow threshold, the system operates normally. If the monitored TFR meets the second flow threshold but does not meet the third flow threshold, the process can determine that the first fluid flow path is blocked. The process can make this determination because the process only detects the flow rate of the second fluid flow path if the flow rate is equal to the expected flow rate of the second fluid flow path. In this manner, the process can determine that the first fluid flow path is blocked because the process does not detect any flow from the first fluid flow path. In some embodiments, the one or more thresholds may be higher or lower than the expected flow rate, for example, to allow for variation during operation.

[0160] In some embodiments, the flow threshold may correspond to a leak rate of the system. For example, the system may have two wound dressings. Each wound dressing may have an associated fluid flow path. A first fluid flow path associated with a first wound dressing includes an air leak of 1 CLP. A second fluid flow path associated with a second wound dressing includes an air leak of 2 CLP. The process 700 may determine that the first flow threshold corresponds to a leak rate of 3 CLP, the second flow threshold corresponds to a leak rate of 2 CLP, and the third flow threshold corresponds to 1 CLP. Thus, if the process detects a TFR of 1 CLP (e.g., meeting the third threshold but not meeting the second or third thresholds), the process may determine that the second fluid flow path is blocked. The process may make this determination because if the TFR is equal to 1 CLP, the system only detects flow in the first fluid flow path. In this way, since the process does not detect flow from the second fluid flow path, the process can determine that the second fluid flow path is blocked. Similarly, if the process detects a TFR of 2 CLP (e.g., the TFR meets the second threshold but not the third threshold), the process can determine that the first fluid flow path is blocked. Similarly, if the process detects a TFR of 3 CLP (e.g., the TFR meets the third threshold), the process can determine that neither the first nor the second fluid flow path is blocked and the system is operating normally. Also, if the process does not sense flow, the process can determine a system blockage with all fluid flow paths being blocked, for example, blocked or the canister is full. As summarized in the following table: [Table 1]

[0161] In some embodiments, one or more of the thresholds may be higher or lower to account for imprecision. For example, the first air leak is equal to 1 CLP, but the first flow threshold provides a small buffer (e.g., 0.03, 0.05, 0.1, 0.15, 0.2, or 0.25 CLP) so that the threshold is slightly below or slightly above 1 CLP. Similar buffers can be used for the other flow thresholds. For example, the first and second thresholds can be 0.5 CLP and 1 CLP, respectively, and the process can make the following determination: [Table 2]

[0162] At block 704, the process 700 monitors the total flow rate (TFR) utilizing one or more of the flow rate monitoring techniques described herein. The process can arbitrate appropriately between flow rates determined using multiple flow rate monitoring techniques if one or more such techniques are performed in parallel. In certain embodiments, the process can perform one of the techniques, such as flow rate determination based on pump speed, and utilize one or more other techniques, if desired. In various embodiments, the process can utilize one or more other techniques if the determined flow rate is perceived to be inaccurate or unreliable. In some embodiments, the total flow rate corresponds to the sum of the flow rates of each flow path in the process. For example, the total flow rate can correspond to the sum of the flow rate of a first fluid flow path and the flow rate of a second fluid flow path.

[0163] In some embodiments, the monitored TFR may be compared to an expected TFR to determine if the system is operating normally. Thus, by comparing the monitored TFR to the expected TFR (e.g., by subtracting the expected TFR from the monitored TFR), process 700 can determine a deviation of the current flow rate from the expected flow rate. This deviation may be due to the presence of one or more operating conditions.

[0164] At block 706, process 700 determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a first flow threshold, which may correspond to an expected TFR. If the first flow threshold is met, at block 708, the system may indicate that the system is operating normally. The instructions at block 708 or any other block of process 700 may be implemented using any of the approaches described herein.

[0165] If the monitored TFR does not meet the first threshold, process 700 transitions to block 710 where it determines whether the monitored TFR meets a second flow threshold. If the second flow threshold is met (e.g., the TFR is substantially equal to or exceeds the second flow threshold), then at block 712, process 700 may indicate that an occlusion condition exists in the first fluid flow path. The process may make this determination because it may determine to detect flow only from the second fluid flow path based on determining that the TFR meets the second threshold (and does not meet the first flow threshold).

[0166] If the monitored TFR does not meet the second threshold, process 700 transitions to block 714, where it determines whether the monitored TFR meets a third flow threshold. If the third flow threshold is met (e.g., the TFR is substantially equal to or exceeds the third threshold), then at block 716, the process may indicate that an occlusion condition exists in the second fluid flow path. Based on determining that the TFR meets the third threshold (and does not meet the first and second thresholds), the process may determine to detect flow only from the first fluid flow path.

[0167] If the monitored TFR does not meet the third threshold, process 700 proceeds to block 718 where it is determined and indicated that the system has been shut down.

[0168] It should be noted that although the examples provided in conjunction with process 700 generally relate to a system having a first and second wound dressing, similar techniques may be implemented for a system having any number of wound dressings.

[0169] Further, it may be understood that fewer, more, or different blocks may be used as part of the process 700. For example, the process 700 may include fewer blocks, for example, if one or more leak rates are equal or approximately equal (e.g., + / - 0.1 L / min or another suitable deviation). As described above, the system may have two wound dressings, and each wound dressing may have an associated fluid flow path. For example, a first fluid flow path associated with a first wound dressing may include an air leak of 1 CLP, and a second fluid flow path associated with a second wound dressing may also include an air leak of 1 CLP. Thus, the process 700 may utilize two flow thresholds, namely, a first flow threshold corresponding to a leak rate of 2 CLP, and a second flow threshold corresponding to a leak rate of 1 CLP. If the process 700 detects a TFR of 1 CLP (e.g., meeting the first threshold but not the second threshold), the process may determine that either the first or second fluid flow path is blocked. Process 700 can make this determination because when the TFR is equal to 1 CLP, the process detects flow from only one fluid flow path. In some cases, the process can determine or indicate which fluid flow path is blocked, while in other cases, the process can determine or indicate if a blockage has occurred somewhere in one of the fluid flow paths. If process 700 detects a TFR of 2 CLP (e.g., the TFR meets the second threshold), the process can determine that neither the first nor the second fluid flow path is blocked and the system is operating normally. Also, if the process does not sense flow, the process can determine a system blockage with all fluid flow paths blocked, for example, a canister full. A summary is provided in the following table. [Table 3]

[0170] 14 shows a flow diagram of a process 800 for determining and indicating one or more operating conditions, according to some embodiments. In some embodiments, the process 800 is implemented by the reduced pressure wound treatment system 600, such as by one or more controllers of the system.

[0171] At block 802, the process 800 determines one or more operating parameters, similar to that described with reference to block 702 of FIG. 7. For example, the process may determine the number of wound dressings attached, whether the fluid flow paths corresponding to the attached wound dressings include air leaks, leak rates of one or more air leaks, a total leak rate, an expected total flow rate (TFR) of the system, an expected flow rate of each fluid flow path, one or more flow thresholds, an activity level of the pump, etc. In some embodiments, the process may perform some or all of such determinations in a calibration mode. Alternatively, some or all of these operating parameters may be automatically detected or received by the process upon application of each wound dressing. In some embodiments, a user may input some or all of the operating parameters, or the process may perform internal calculations or utilize conversion equations or tables.

[0172] As described herein, the process 800 may detect the presence of one or more attached wound dressings by detecting a higher than expected leak rate. For example, the process may automatically detect the presence of a W-connector by detecting a leak higher than expected leak rate and prompt the user to confirm that another flow path is present. Once the user confirms, the process may know how to detect an obstruction. In other embodiments, the process may detect when a wound dressing is attached and may know the specification as an air leak section based on the attached wound dressing.

[0173] Process 800 may determine multiple flow thresholds. In this example, the process may determine at least seven flow thresholds. However, it is noted that more or fewer flow thresholds may be determined. As described with respect to block 702 of FIG. 7, the flow thresholds may correspond to the TFR of the system in the presence of one or more operating conditions.

[0174] In some embodiments, the first flow threshold corresponds to a flow rate equal to the sum of the expected flow rate of the first fluid flow path (expected first flow rate), the expected flow rate of the second fluid flow path (expected second flow rate), and the expected flow rate of the third fluid flow path (expected third flow rate). The second flow threshold corresponds to a flow rate equal to the sum of the expected second flow rate and the expected third flow rate. The third flow threshold corresponds to a flow rate equal to the sum of the expected first flow rate and the expected third flow rate. The fourth flow threshold corresponds to a flow rate equal to the sum of the expected first flow rate and the expected second flow rate. The fifth flow threshold corresponds to a flow rate equal to the expected third flow rate. The sixth flow threshold corresponds to a flow rate equal to the expected second flow rate. The seventh flow threshold corresponds to a flow rate equal to the expected first flow rate.

[0175] For example, a first fluid flow path may have a leak rate of 1 CLP, a second fluid flow path may have a leak rate of 3 CLP, and a third fluid flow path may have a leak rate of 5 CLP. The first flow threshold corresponds to a leak rate equal to 9 CLP (e.g., the sum of all leak rates). The second flow threshold corresponds to a leak rate equal to 8 CLP. The third flow threshold corresponds to a leak rate equal to 6 CLP. The fourth flow threshold corresponds to a leak rate equal to 5 CLP. The fifth flow threshold corresponds to a leak rate equal to 4 CLP. The sixth flow threshold corresponds to a leak rate equal to 3 CLP. The seventh flow threshold corresponds to a leak rate equal to 1 CLP. This is outlined below: [Table 4]

[0176] In some embodiments, the order of the flow thresholds may vary based on the leak rate of the air leak.

[0177] At block 804, similar to that described with reference to block 704 of FIG. 7, process 800 monitors the TFR utilizing one or more flow monitoring techniques described herein.

[0178] At block 806, process 800 determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a first flow threshold. If the first flow threshold is met, at block 808, the process may indicate that the system is operating normally. The instructions at block 808 or any other block of process 800 may be implemented using any of the approaches described herein.

[0179] If the monitored TFR does not meet the first flow threshold, the process transitions to block 810 to determine whether the monitored TFR meets (e.g., substantially equals or exceeds) a second flow threshold. If the second flow threshold is met (and the first flow threshold is not met), then at block 812, the process may indicate that an occlusion condition exists in the first fluid flow path. The process may make this determination because, based on the met thresholds, the process may determine to only detect flow from the second and third fluid flow paths.

[0180] If the monitored TFR does not meet the second flow threshold, the process transitions to block 814, where it determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a third flow threshold. If the third flow threshold is met (and the first and second flow thresholds are not met), then at block 816, the process may indicate that an occlusion condition exists in the second fluid flow path. The process may make this determination because, based on the met thresholds, the process may determine to detect flow only from the first and third fluid flow paths.

[0181] If the monitored TFR does not meet the third flow threshold, the process transitions to block 818, where it determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a fourth flow threshold. If the fourth flow threshold is met (and the first, second, and third flow thresholds are not met), then at block 820, the process may indicate that an occlusion condition exists in the first and second fluid flow paths. The process may make this determination because, based on the met thresholds, the process may determine to detect flow only from the third fluid flow path.

[0182] If the monitored TFR does not meet the fourth flow threshold, the process transitions to block 822, where it determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a fifth flow threshold. If the fifth flow threshold is met (and the first through fourth flow thresholds are not met), then at block 824, the process may indicate that an occlusion condition exists in the third fluid flow path. The process may make this determination because, based on which thresholds are met, the process may determine that it detects flow only from the first and second fluid flow paths.

[0183] If the monitored TFR does not meet the fifth flow threshold, the process transitions to block 826, where it determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a sixth flow threshold. If the sixth flow threshold is met (and the first through fifth flow thresholds are not met), then at block 828, the process may indicate that an occlusion condition exists in the first and third fluid flow paths. The process may make this determination because, based on the met thresholds, the process may determine to detect flow only from the second fluid flow path.

[0184] If the monitored TFR does not meet the sixth flow threshold, the process transitions to block 830, where it determines whether the monitored TFR meets (e.g., substantially equals or exceeds) a seventh flow threshold. If the seventh flow threshold is met (and the first through sixth flow thresholds are not met), then at block 832, the process may indicate that an occlusion condition exists in the third fluid flow path. The process may make this determination because, based on the met thresholds, the process may determine that it detects flow only from the first fluid flow path.

[0185] At block 834, the process 800 determines that the flow threshold has not been met, indicating a system shutoff condition.

[0186] It should be noted that although the examples provided in conjunction with process 800 relate to a system having a first, second and third wound dressing, similar techniques may be implemented for a system having any number of wound dressings.

[0187] Further examples, embodiments, methods, processes, or devices for a negative pressure wound therapy system with calibrated leak paths are provided in International Application No. PCT / EP2018 / 056494, entitled "MULTIPLE DRESSING NEGATIVE PRESSURE WOUND THERAPY SYSTEM WITH CLALIBRATED LEAK PATHS," filed March 15, 2018, which is incorporated by reference in its entirety herein.

[0188] term In some embodiments, certain operations, acts, events, or functions of any of the processes described herein may be performed in differing orders, and may be added, combined, or removed (e.g., not all are required to practice the process) as a whole (e.g., as necessary to practice the process). Furthermore, in certain embodiments, operations, acts, functions, or events may be performed simultaneously rather than sequentially, for example, through multithreaded processing, interrupt processing, or multiple processors or processor cores, or on other parallel architectures.

[0189] Processing of the various components of the illustrated system may be distributed across multiple machines, networks, and other computing resources. Additionally, two or more components of the system may be combined into fewer components. Various components of the illustrated system may be implemented in one or more virtual machines rather than dedicated computer hardware systems and / or computing devices. Similarly, the illustrated data repositories may represent physical and / or logical data stores, including, for example, storage area networks or other distributed storage systems. Additionally, in some embodiments, the connections between the illustrated components represent possible paths for data flow, rather than actual connections between hardware. Although some examples of possible connections are shown, any subset of the illustrated components may communicate with any other subset of the components in various implementations.

[0190] The above patents and specifications and other references, including those that may be described in accompanying application documents, are incorporated herein by reference. Aspects of the present disclosure can be modified, if necessary, to provide still further implementations using the systems, functions, and concepts of the various references described herein.

[0191] It is to be understood that a property, substance, feature, or group described in connection with a particular aspect, embodiment, or example may be applied to any other aspect, embodiment, or example described herein, unless incompatible therewith. All features disclosed in this specification (including any accompanying claims, abstract, and drawings), or all steps of any method or process similarly disclosed, may be combined in any combination, except combinations in which at least some of such features or steps are mutually exclusive. The subject matter is not limited to the details of any of the foregoing embodiments. The subject matter extends to any novel, or any novel combination, of features disclosed in this specification (including any accompanying claims, abstract, and drawings), or any novel, or any novel combination of steps of any method or process similarly disclosed.

[0192] Although specific embodiments have been described, these embodiments are presented merely as examples and are not intended to limit the scope of protection. Indeed, the novel methods and systems described herein may be embodied in various other forms. Furthermore, various omissions, substitutions, and changes may be made in the form of the methods and systems described herein. Those skilled in the art will appreciate that in some embodiments, the actual steps performed in the illustrated or disclosed processes may differ from those shown in the drawings. In some embodiments, certain steps of the steps described above may be omitted, or others may be added. For example, the actual steps or order of steps performed in the disclosed processes may differ from those shown in the drawings. In some embodiments, certain steps of the steps described above may be omitted, or others may be added. For example, various components illustrated in the drawings may be implemented as software or firmware on a processor, controller, ASIC, FPGA, or dedicated hardware. Hardware components such as processors, ASICs, FPGAs, etc. may include logic circuits. Furthermore, the features and characteristics of the specific embodiments disclosed above can be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure.

[0193] Although the present disclosure includes certain embodiments, examples, and applications, it will be understood by those skilled in the art that the present disclosure extends beyond the scope of the specifically disclosed embodiments to other alternative embodiments or uses, as well as obvious modifications and equivalents thereof, including embodiments that do not provide all of the features and advantages described herein. Thus, the scope of the present disclosure is not intended to be limited by the described embodiments, but may be defined by the claims presented herein or hereafter.

[0194] Conditional language such as "can," "could," "might," or "may," unless specifically stated otherwise or interpreted otherwise within the context in which it is used, is typically intended to convey that certain embodiments include certain features, elements, or steps, while other embodiments do not. Thus, such conditional language is not generally intended to imply that features, elements, or steps are in any way required by one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without user input or instructions, whether those features, elements, or steps are included in or should be performed in any particular embodiment. Terms such as "comprises," "including," and "having" are synonymous and are used in an inclusive, open-ended manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in an inclusive sense (rather than an exclusive sense), such that, for example, when used to join a list of elements, the term "or" means one, some, or all of the elements in the list. Similarly, the term "and / or," in relation to a list of two or more items, encompasses all of the following interpretations of the word: any one of the items in the list, all the items in the list, and any combination of the items in the list. Additionally, the term "each," as used herein, in addition to having its ordinary meaning, may also refer to any subset of the set of elements to which the term "each" is applied. Additionally, as used herein, the terms "herein," "above," "below," and similar terms, when used in this application, are meant to refer to this specification as a whole, and not to any particular portions of this specification.

[0195] Conjunctive phrases such as "at least one of X, Y, and Z," unless specifically stated otherwise, are to be construed otherwise in accordance with the context in which they are generally used to suggest that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive phrases are not necessarily intended to suggest that a particular embodiment requires that it includes at least one X, at least one Y, and at least one Z.

[0196] As used herein, degree-expressing phrases such as "approximately," "about," "generally," and "substantially" refer to a value, amount, or characteristic that is close to a given value, amount, or characteristic that still performs a desired function or produces a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within 10%, 5%, 1%, 0.1%, and 0.01% of a given amount. As another example, in certain embodiments, the terms "generally parallel" and "substantially parallel" refer to a value, amount, or characteristic that deviates from exactly parallel by 15 degrees or less, 10 degrees, 5 degrees, 3 degrees, 1 degree, or 0.1 degrees.

[0197] Any of the embodiments described herein can be used with or without a canister. Any of the dressing embodiments described herein can absorb and store wound exudate.

[0198] The scope of the present disclosure is not intended to be limited by the description of the specific embodiments, but may be defined by the claims, which claim language should be interpreted broadly based on the language used in the claims and not limited to the examples described herein or during the prosecution of this application, which examples should be interpreted as non-exclusive. [Additional note 1] 1. A fluid connector for negative pressure wound therapy, comprising: a top layer, a bottom layer and a middle layer, each layer constructed from a flexible liquid impermeable material, each layer including a proximal end and a distal end; an upper fluid passage at least partially defined between the top layer and the middle layer, the upper fluid passage including a proximal end and a distal end, the upper fluid passage comprising an upper channel spacer material positioned between the top layer and the middle layer, the upper fluid passage configured to provide gas from an opening in the top layer located at or near the proximal end of the upper fluid passage; a lower fluid passage at least partially defined between the middle layer and the bottom layer, the lower fluid passage configured to be in fluid communication with a source of negative pressure, the lower fluid passage comprising a lower channel spacer material positioned between the middle layer and the bottom layer; an opening at the distal end of the bottom layer configured to be positioned over an opening in a dressing configured to be positioned over a wound, the opening in the bottom layer fluidly connected to the lower fluid passage; an opening at the distal end of the middle layer, the opening in the middle layer fluidly connected to the top fluid passage, the opening in the middle layer positioned above the opening in the bottom layer; a distal end of the upper channel spacer material extends further distally than a distal end of the lower channel spacer material, the lower fluid passage having a portion at a distal end free of the lower channel spacer material, the portion of the lower fluid passage including the opening in the bottom layer; A fluid connector for negative pressure wound treatment, wherein when negative pressure is applied to the lower fluid passage from the negative pressure source, the portion of the lower fluid passage collapses, blocking fluid flow between the lower channel spacer material and the upper channel spacer material through the portion of the lower fluid passage, but allowing fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the covering material, the opening in the bottom layer, and the opening in the middle layer. [Additional note 2] 1. A fluid connector for negative pressure wound therapy, comprising: a top layer, a bottom layer and a middle layer, each layer constructed from a flexible liquid impermeable material, each layer including a proximal end and a distal end; an upper fluid passage at least partially defined between the top layer and the middle layer, the upper fluid passage including a proximal end and a distal end, the upper fluid passage comprising an upper channel spacer material positioned between the top layer and the middle layer, the upper fluid passage configured to provide gas from an opening in the top layer located at or near the proximal end of the upper fluid passage; a lower fluid passage at least partially defined between the middle layer and the bottom layer, the lower fluid passage configured to be in fluid communication with a source of negative pressure, the lower fluid passage comprising a lower channel spacer material positioned between the middle layer and the bottom layer; one or more openings at the distal end of the bottom layer, the one or more openings in the bottom layer configured to be positioned over an opening in a dressing configured to be positioned over a wound, at least one of the one or more openings in the bottom layer fluidly connected to the lower fluid passage; an opening at the distal end of the middle layer, the opening in the middle layer fluidly connected to the top fluid passage, the opening in the middle layer positioned above at least one of the one or more openings in the bottom layer; A fluid connector for negative pressure wound treatment, wherein a distal end of the upper channel spacer material extends further distally than at least a portion of the distal end of the lower channel spacer material, whereby the lower fluid passage has a portion at its distal end that is free of the lower channel spacer material, and the portion of the lower fluid passage includes the one or more openings in the bottom layer. [Additional note 3] 3. The fluid connector of claim 2, wherein when negative pressure is applied to the lower fluid passage from the negative pressure source, the portion of the lower fluid passage collapses, blocking fluid flow between the lower channel spacer material and the upper channel spacer material through the portion of the lower fluid passage, but allowing fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the covering material, the one or more openings in the bottom layer, and the opening in the middle layer. [Additional note 4] A fluid connector as described in any one of the preceding paragraphs, wherein a portion of the lower channel spacer material at the distal end overlaps the opening or one of the one or more openings in the bottom layer. [Additional note 5] 13. The fluid connector of any one of the preceding claims, further comprising an applicator attached to the bottom layer at the distal end, the applicator comprising an adhesive configured to be adhered to the covering material. [Additional note 6] A fluid connector as described in any one of the preceding paragraphs, wherein the applicator has an opening disposed immediately below the opening or the one or more openings in the bottom layer and configured to be positioned over the opening in the covering material. [Additional note 7] 13. The fluid connector of any one of the preceding claims, wherein at least a portion of the opening in the intermediate layer overlaps with the opening in the applicator. [Additional note 8] 13. A fluid connector according to any one of the preceding claims, wherein the opening or the one or more openings in the bottom layer are wider than the opening in the middle layer. [Additional note 9] A fluid connector according to any one of the preceding claims, wherein the centre of the opening in the middle layer is positioned further distal than the centre of the or each of the one or more openings in the bottom layer. [Additional Note 10] 7. The fluid connector of any one of the preceding claims, wherein the upper channel spacer material comprises foam. [Additional Note 11] 13. The fluid connector of any one of the preceding claims, wherein the lower channel spacer material comprises a 3D knit or 3D woven material. [Additional Note 12] 13. The fluid connector of any one of the preceding claims, wherein the top layer and the bottom layer each have an enlarged distal end. [Additional Note 13] 13. The fluid connector of claim 12, wherein the extended ends of the top and bottom layers are rectangular. [Additional Note 14] 13. The fluid connector of claim 12, wherein the extended ends of the top layer and the bottom layer form a teardrop shape. [Additional Note 15] 13. The fluid connector of any one of the preceding claims, wherein the bottom layer is configured to be attached to the covering material. [Additional Note 16] 7. The fluid connector of any one of the preceding claims, wherein the opening in the top layer comprises a filter. [Additional Note 17] A fluid connector as described in any one of the preceding paragraphs, further comprising a connector in fluid communication with a proximal end of the lower channel spacer material, the connector being configured to be fluidly connected to the negative pressure source. [Additional Note 18] 18. The fluid connector according to any one of claims 2 to 17, wherein the lower fluid passage comprises a welded portion in which a portion of the bottom layer is welded to the middle layer. [Additional Note 19] 19. The fluid connector of claim 18, wherein when negative pressure is applied to the lower fluid passage from the negative pressure source, the welded portion of the lower fluid passage blocks fluid flow between the lower channel spacer material and the upper channel spacer material through the portion of the lower fluid passage but allows fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the coating material, the one or more openings in the bottom layer, and the opening in the middle layer. [Additional Note 20] 20. The fluid connector of claim 18 or 19, wherein the portion of the lower fluid passage includes a distal portion and a proximal portion, the distal portion being separated from the proximal portion by the welded portion of the lower fluid passage. [Additional Note 21] 21. The fluid connector of any one of claims 18 to 20, wherein the one or more openings in the bottom layer include two openings. [Additional Note 22] 22. The fluid connector of claim 21, wherein the welded portion of the bottom layer is located between the two openings. [Additional Note 23] 23. The fluid connector of claim 21 or 22, wherein at least one of the two openings has a semicircular shape. [Additional note 24] 24. The fluid connector of any one of claims 2 to 23, wherein the distal end of the lower channel spacer material includes a fork shape with a base portion between two side portions, the two side portions extending distally from the base portion, the one or more openings in the bottom layer, and the opening in the middle layer, and the base portion is proximal to the one or more openings in the bottom layer and the opening in the middle layer. [Additional note 25] 25. The fluid connector of claim 24, wherein the portion of the lower fluid passage is positioned between the two side portions of the lower channel spacer material and distal to the base portion of the lower channel spacer material. [Additional note 26] 1. A fluid connector for negative pressure wound therapy, comprising: an upper fluid passage configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage; a lower fluid passage in fluid communication with a negative pressure source and configured to allow fluid to flow through the lower fluid passage toward the negative pressure source; an intermediate layer between the upper fluid passage and the lower fluid passage, the intermediate layer comprising a fluid impermeable material; and one or more first openings at a distal end of the lower fluid passage, the one or more first openings configured to be positioned over an opening in a dressing configured to be positioned over a wound; a second opening at a distal end of the middle layer, the second opening being positioned above at least one of the one or more first openings in the bottom layer, the second opening being fluidly connected to the upper fluid passage; the upper fluid passage extends further distally than the lower fluid passage, the lower fluid passage comprising an open portion in which the one or more first openings are located; A fluid connector, wherein when negative pressure is applied from the negative pressure source to the lower fluid passage, fluid flow is blocked between the upper fluid passage and the lower fluid passage through the open portion, but allows fluid flow between the upper fluid passage and the lower fluid passage through the dressing and a filler positioned within the wound. [Additional note 27] 27. A fluid connector as described in claim 26, wherein the void portion collapses in response to negative pressure applied to the lower fluid passage, thereby blocking fluid flow between the upper fluid passage and the lower fluid passage through the void portion. [Additional note 28] 27. The fluid connector of claim 26, wherein the gap includes a welded portion at which a portion of the bottom layer is welded to the middle layer, and the welded portion is configured to block fluid flow between the upper fluid passage and the lower fluid passage through the gap when negative pressure is applied to the lower fluid passage. [Additional note 29] 30. The fluid connector of claim 28, wherein the open portion of the lower fluid passage comprises a distal portion and a proximal portion, the distal portion being separated from the proximal portion by the welded portion of the lower fluid passage. [Additional note 30] 30. The fluid connector of claim 28 or 29, wherein the one or more openings in the bottom layer include two openings. [Additional note 31] 31. The fluid connector of claim 30, wherein the welded portion of the bottom layer is located between the two openings. [Additional note 32] 32. A fluid connector as described in claim 30 or 31, wherein at least one of the two openings is semicircular in shape. [Additional note 33] 33. The fluid connector of any one of claims 26 to 32, wherein the lower fluid passage comprises a lower channel spacer material, and a portion of the lower channel spacer material at the distal end of the lower fluid passage overlaps one of the one or more first openings. [Additional note 34] 34. A fluid connector as described in any one of appended claims 26 to 33, wherein the lower fluid passage comprises a lower channel spacer material, and a portion of the lower channel spacer material at the distal end of the lower fluid passage abuts a distal edge of one of the one or more first openings. [Additional note 35] 35. The fluid connector of any one of appended claims 26 to 34, wherein the lower fluid passage comprises a lower channel spacer material, and a portion of the lower channel spacer material at the distal end of the lower fluid passage comprises a fork shape with a base portion between two side portions, the two side portions extending distally from the base portion, the one or more first openings in the bottom layer and the opening in the middle layer, and the base portion is proximal to the first one or more openings in the bottom layer and the opening in the middle layer. [Additional note 36] 36. The fluid connector of claim 35, wherein the portion of the lower fluid passage is positioned between the two side portions of the lower channel spacer material and distal to the base portion of the lower channel spacer material. [Additional note 37] 37. The fluid connector of any one of claims 26 to 36, further comprising an applicator attached to a bottom surface of the fluid connector at a distal end, the applicator comprising an adhesive configured to be adhered to the covering material. [Additional note 38] 38. The fluid connector of claim 37, wherein the applicator has an opening immediately below the one or more first openings and is configured to be positioned over the opening in the covering material. [Additional note 39] 39. The fluid connector of claim 37 or 38, wherein at least a portion of the second opening overlaps with the opening in the applicator. [Additional note 40] 40. The fluid connector of any one of claims 26 to 39, wherein the one or more first openings are wider than the second openings. [Additional note 41] 41. The fluid connector of any one of claims 26 to 40, wherein the center of the second opening is positioned further distal from the center of each of the one or more first openings. [Additional note 42] 42. The fluid connector according to any one of claims 26 to 41, wherein the gas comprises air. [Additional note 43] 1. A method of operating a negative pressure wound therapy system, the method comprising: A suction adaptor is provided, the suction adaptor comprising: an upper fluid passage configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage; a lower fluid passage in fluid communication with a negative pressure source and configured to allow fluid to flow through the lower fluid passage toward the negative pressure source; an intermediate layer between the upper fluid passage and the lower fluid passage, the intermediate layer comprising a fluid impermeable material; and one or more first openings at a distal end of the lower fluid passage, the one or more first openings configured to be positioned over an opening in a dressing configured to be positioned over a wound; a second opening at a distal end of the middle layer, the second opening being positioned above at least one of the one or more first openings in the bottom layer, the second opening being fluidly connected to the upper fluid passage; providing a suction adapter, the upper fluid passage extending further distally than the lower fluid passage, the lower fluid passage comprising an open portion in which the one or more first openings are located; applying negative pressure from the negative pressure source to the wound through the lower fluid passage of the suction adapter; blocking fluid flow between the upper fluid passage and the lower fluid passage through the open portion at an open portion but allowing at least some gas from the upper fluid passage to flow through the dressing and wound filler positioned at the wound, and further allowing gas to be suctioned through the lower fluid passage when the suction adapter is attached to the dressing and the one or more first openings are positioned in fluid communication with the openings in the dressing. [Additional note 44] A method of operating a negative pressure wound treatment system as described in claim 43, wherein applying negative pressure from the negative pressure source to the wound through the lower fluid passage of the suction adapter causes the voids to collapse, thereby selectively blocking the fluid flow. [Additional note 45] A method of operating a negative pressure wound treatment system as described in Appendix 43, wherein the open portion comprises a welded portion where the bottom layer is welded to the middle layer, whereby the welded portion selectively blocks the fluid flow while the negative pressure from the negative pressure source is applied to the wound through the lower fluid passage of the suction adapter. [Additional note 46] A fluid connector comprising one or more of the features described and / or illustrated, a method of using a fluid connector comprising one or more of the features described and / or illustrated, a negative pressure wound therapy device comprising one or more of the features described and / or illustrated, a method of operating a negative pressure wound therapy device comprising one or more of the features described and / or illustrated, and / or a method of treating a wound comprising one or more of the features described and / or illustrated.

Claims

1. 1. A fluid connector for negative pressure wound therapy, comprising: a top layer, a bottom layer and a middle layer, each of said layers constructed from a flexible liquid impermeable material, each of said layers including a proximal end and a distal end; an upper fluid passage at least partially defined between the top layer and the middle layer, the upper fluid passage including a proximal end and a distal end, the upper fluid passage comprising an upper channel spacer material positioned between the top layer and the middle layer, the upper fluid passage configured to provide gas from an opening in the top layer located at or near the proximal end of the upper fluid passage; a lower fluid passage at least partially defined between the middle layer and the bottom layer, the lower fluid passage configured to be in fluid communication with a source of negative pressure, the lower fluid passage comprising a lower channel spacer material positioned between the middle layer and the bottom layer; one or more openings at the distal end of the bottom layer configured to be positioned over an opening in a dressing configured to be positioned over a wound, at least one of the one or more openings in the bottom layer fluidly connected to the lower fluid passage; an opening at the distal end of the middle layer, the opening in the middle layer fluidly connected to the top fluid passage, the opening in the middle layer positioned above at least one of the one or more openings in the bottom layer; A fluid connector for negative pressure wound treatment, wherein the distal end of the upper channel spacer material extends further distally than at least a portion of the distal end of the lower channel spacer material, whereby the lower fluid passage has a portion at its distal end that is free of the lower channel spacer material, and the portion of the lower fluid passage includes one or more of the openings in the bottom layer.

2. 2. The fluid connector of claim 1, wherein when negative pressure is applied to the lower fluid passage from the negative pressure source, the portion in the lower fluid passage collapses, blocking fluid flow between the lower channel spacer material and the upper channel spacer material through the portion in the lower fluid passage, but allowing fluid flow between the lower channel spacer material and the upper channel spacer material through the opening in the covering material, the one or more openings in the bottom layer, and the opening in the middle layer.

3. 3. The fluid connector of claim 1 or 2, wherein a portion of the lower channel spacer material at the distal end overlaps one of the opening or one or more of the openings in the bottom layer.

4. 4. The fluid connector of claim 1, further comprising an applicator attached to the bottom layer at the distal end, the applicator including an adhesive configured to be adhered to the dressing.

5. the applicator comprises an opening disposed immediately below the opening or one or more openings in the bottom layer and configured to be positioned over the opening in the dressing.

5. The fluid connector of claim 1, wherein optionally at least a portion of the opening in the intermediate layer overlaps with the opening in the applicator.

6. 6. A fluid connector according to claim 1, wherein the or one or more of the openings in the bottom layer are wider than the opening in the middle layer.

7. 7. The fluid connector of claim 1, wherein the center of the opening in the middle layer is positioned further distally than the center of the or each of the one or more openings in the bottom layer.

8. the upper channel spacer material comprises a foam; or The fluid connector of claim 1 , wherein the lower channel spacer material comprises a 3D knit or 3D woven material.

9. each of the top layer and the bottom layer having an enlarged distal end; 9. The fluid connector of claim 1, wherein optionally the extended ends of the top and bottom layers are rectangular or form a teardrop shape.

10. 10. The fluid connector of claim 1, wherein the bottom layer is configured to be attached to the covering material.

11. The fluid connector of claim 1 , wherein the opening in the top layer comprises a filter.

12. 12. The fluid connector of claim 1, further comprising a connector in fluid communication with a proximal end of the lower channel spacer material, the connector configured to be fluidly connected to the negative pressure source.

13. 13. The fluid connector of claim 1, wherein the distal end of the lower channel spacer material includes a fork shape with a base portion between two side portions, the two side portions extending distally from the base portion, the one or more openings in the bottom layer, and the opening in the middle layer, and the base portion is proximal to the one or more openings in the bottom layer and the opening in the middle layer.

14. The fluid connector of claim 13 , wherein the portion of the lower fluid passage is positioned between the two side portions of the lower channel spacer material and distal to the base portion of the lower channel spacer material.

15. 1. A fluid connector for negative pressure wound therapy, comprising: an upper fluid passage configured to provide gas from an opening located at or near a proximal end of the upper fluid passage toward a distal end of the upper fluid passage; a lower fluid passage in fluid communication with a negative pressure source and configured to allow fluid to flow through the lower fluid passage toward the negative pressure source; an intermediate layer between the upper fluid passage and the lower fluid passage, the intermediate layer comprising a fluid impermeable material; and one or more first openings at a distal end of the lower fluid passage, the one or more first openings configured to be positioned over an opening in a dressing configured to be positioned over a wound; a second opening at a distal end of the middle layer, the second opening being positioned above at least one of the one or more first openings in the bottom layer, the second opening being fluidly connected to the upper fluid passage; the upper fluid passage extends further distally than the lower fluid passage, the lower fluid passage comprising an open portion in which one or more of the first openings are located; A fluid connector, wherein when negative pressure is applied from the negative pressure source to the lower fluid passage, fluid flow is blocked between the upper fluid passage and the lower fluid passage through the open portion, but allows fluid flow between the upper fluid passage and the lower fluid passage through the dressing and a filler positioned within the wound.

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