Low profile filter device suitable for use in negative pressure wound therapy systems

Abstract

The filter adapter includes a body defining an internal passageway disposed between an inlet and an outlet, the passageway configured to allow fluid passage in a first direction defined by the inlet and the outlet, and a filter disposed within the passageway and oriented to define a volumetric direction different from the first direction. Another filter adapter includes a body defining an internal passageway disposed between the inlet and the outlet, and a filter disposed within the passageway, the filter comprising a gelling absorbent material that is gas permeable in a dry state and converts to a gel upon contact with an aqueous fluid. Such a filter adapter may be used in negative pressure wound therapy, a dressing, or a syringe filter.

Description

[Background technology]

[0001] Fluid filters in various medical applications are subject to various limitations, some of which are related to the resistance to fluid flow presented by the filter. For example, in a fluid system in which a large volume of fluid is passed through a filter, the rate at which the fluid passes through the filter is limited by several factors, such as the physical properties of the filter material, the physical properties of the fluid, and the surface area of ​​the filter available for fluid passage. These and other limitations can cause pressure buildup at the filter site, resulting in fluid backup at levels that are unacceptable given the flow characteristics of the filter.

[0002] With respect to filters designed for use in filtering fluids flowing through conduits such as catheters, syringes, rubber tubing, and the like, such filters are conventionally provided in the form of devices that are fluidly connected to the conduits, also referred to herein as "filter adapters," which position the filter in the fluid flow path in an orientation perpendicular to the direction of fluid flow. A conventional method of improving fluid flow through such filters is to increase the diameter of the filter, thereby increasing the surface area of ​​the filter operable to allow the passage of the fluid to be filtered. However, increasing the diameter of the filter and / or filter adapter creates problems in many applications of such filters. For example, when the filter adapter is used in connection with a fluid system that requires the tubing to be placed against the patient's skin, or in fluid flow tubing where the adapter would be placed in the tubing between a wound dressing and a pump, such as occurs in negative pressure wound therapy systems, a larger diameter filter adapter is undesirable because it can become unwieldy, can cause pressure damage to the patient's skin or other tissues remote from the wound site, and / or can become entangled in the patient's clothing, causing damage to the clothing and / or disturbing the wound. Not only is this painful to the patient, but it can also lead to the dressing becoming dislodged or the vacuum underneath the dressing becoming reduced in the case of negative pressure wound therapy. Summary of the Invention [Problem to be solved by the invention]

[0003] In view of the above, there exists a need for a fluid filter system having a low profile and a filter adapter that is compact enough to minimize impact on the patient while filtering fluid flow at an acceptable rate with minimal pressure drop across the filter. The present disclosure addresses these needs. [Means for solving the problem]

[0004] The present disclosure provides a low profile filter device suitable for use in negative pressure wound therapy systems and other systems where fluid filtration is desired. In one aspect of the disclosure, a filter adapter is provided that includes: (i) a body defining an internal passageway disposed between an inlet and an outlet, the body configured to permit the passage of a fluid in a first direction defined by the inlet and the outlet; and (ii) a filter disposed within the passageway and oriented to define a volumetric direction different from the first direction. In some embodiments, the volumetric direction is perpendicular to the first direction. In some embodiments, the volumetric direction and the first direction are offset by an angle of at least 15°.

[0005] In some embodiments, the filter adapter has a tubular shape and has an outer diameter, and the filter has a surface area that is independent of the outer diameter, hi some embodiments, the outer diameter is between about 3 mm and about 15 mm.

[0006] In some embodiments, the filter is cylindrical. In some embodiments, the filter is planar. In some embodiments, the filter lies on a plane that is not perpendicular to the first direction. In some embodiments, the filter lies on a plane that forms an angle with the first direction, where the angle is less than 45°. In some embodiments, the filter comprises a gas permeable material. In some embodiments, the filter comprises a liquid impermeable material. In some embodiments, the filter is gas permeable and liquid impermeable. In some embodiments, the filter is hydrophobic.

[0007] In some embodiments, the body includes a first connector at the inlet and a second connector at the outlet. In some embodiments, each of the first and second connectors comprises a barbed connector, a hose connector, or a luer connector. In some embodiments, the first adapter further comprises an indicator disposed within the internal passageway. In some embodiments, the indicator detects an occlusion or a need for a dressing change. In some embodiments, the indicator sensor comprises a change in a symbol, letter, number, or color.

[0008] Another aspect of the present disclosure provides a filter adapter including: (i) a body defining an internal passageway disposed between an inlet and an outlet; and (ii) a filter disposed within the passageway, the filter having a gelling absorbent material that is permeable to gases when dry and that converts to a gel upon contact with an aqueous fluid. In some embodiments, the gelling absorbent material includes gel-forming fibers. In some embodiments, the gelling absorbent material comprises compressed gel-forming fibers. In some embodiments, the compressed gel-forming fibers have a density of about 10 to about 70 kg / cm. 3 In some embodiments, the internal passage comprises a helical path.

[0009] Further features, characteristics, and embodiments of the present disclosure will become apparent from the detailed description herein.

[0010] [Incorporated by reference] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a side elevational view of one filter adapter embodiment according to the present disclosure. [Diagram 2] 2 is a cross-sectional view of the embodiment of the filter adapter shown in FIG. [Diagram 3] 3 is a perspective view of the body of the embodiment of the filter adapter shown in FIG. 1. FIG. [Figure 4] 4 is a cross-sectional view of the body of the embodiment of the filter adapter shown in FIG. [Diagram 5] 5 is a perspective view of the body and filter of the embodiment of the filter adapter shown in FIG. 1. FIG. [Figure 6] 6 is a cross-sectional view of the filter of the embodiment of the filter adapter shown in FIG. [Figure 7] 7 is a perspective view of the body, filter, and indicator of the embodiment of the filter adapter shown in FIG. 1. FIG. [Figure 8] 8 is a cross-sectional view of the indicator of the embodiment of the filter adapter shown in FIG. [Figure 9] 9 is a cross-sectional view of the housing of the embodiment of the filter adapter shown in FIG. [Figure 10] 10 is a perspective view of the embodiment of the filter adapter shown in FIG. [Figure 11] FIG. 11 shows the filter adapter of FIG. 1 connected to a wound dressing. [Figure 12] FIG. 12 is a perspective view of another filter adapter embodiment in accordance with the present disclosure within a tube. [Figure 13] 13 is a perspective view of the embodiment of the filter adapter shown in FIG. [Figure 14] FIG. 14 is a cross-sectional view of the embodiment of the filter adapter shown in FIG. 12 inside a tube. [Figure 15] FIG. 15 is a perspective view of another filter adapter embodiment according to the present disclosure. [Figure 16] 16 is a cross-sectional view of the embodiment of the filter adapter shown in FIG. 15 with an exploded view of the filter. [Figure 17] FIG. 17 is a schematic diagram of another filter adapter embodiment in accordance with the present disclosure. [Figure 18] FIG. 18 is a top view of another filter adapter embodiment in accordance with the present disclosure. [Figure 19] 19 is an exploded view of the embodiment of the filter adapter shown in FIG. [Figure 20] FIG. 20 shows the filter adapter embodiment of FIG. 18 connected to a wound dressing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] It should be understood that the drawings are not necessarily to scale, and that the disclosed embodiments are at times diagrammatically and partially illustrated. In certain instances, details that are not necessary for an understanding of the disclosed methods and apparatuses, or that make other details difficult to perceive, may be omitted. It should be further understood that the present disclosure is not limited to the specific embodiments illustrated herein.

[0013] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments described herein and illustrated in the drawings, and specific language will be used to describe the embodiments. The embodiments of the present application described below are not intended to be exhaustive or to limit the teachings of the present application to the precise forms disclosed in the following detailed description. Rather, the embodiments are selected and described so that others skilled in the art can appreciate and understand the principles and practices of the present application. It will therefore be understood that no limitation of the scope of the invention is intended by the description of the specific embodiments. Any changes and further modifications in the described embodiments, and any further applications of the principles of the present invention as described herein, are contemplated as would normally occur to one skilled in the art to which the invention pertains.

[0014] Described herein is a compact filter device for use with medical equipment, including wound dressings and other negative pressure wound therapy devices, capable of filtering large volumes of fluid. While certain embodiments described herein are configured as filter adapters that can be connected to or disposed within a fluid conduit, it is understood that the present disclosure also contemplates that the filter apparatus may alternatively be configured as part of a fluid conduit or other device that defines a fluid flow path as an integral configuration. As a corollary, while various filter adapter embodiments described herein include structure for engaging the filter adapter to a conduit, such as luer connectors, barbed fittings, and various other types of connectors, it is understood that embodiments of the filter apparatus that are assembled as an integral part of a fluid conduit or other device that defines a fluid flow path will omit such connectors.

[0015] In various filter adapter embodiments and method and process embodiments disclosed herein, the filtering capacity of a filter adapter, generally having a tubular design, under a given set of conditions, e.g., pressure, flow rate, etc., can be increased by increasing the tubular length, which correspondingly increases the working surface area of ​​the filter, without changing the diameter of the filter adapter. In other embodiments, adapter filters having the features as described herein can have other elongated shapes without departing from the principles of the present disclosure, e.g., elongated shapes having an outer cross-sectional shape that is oval, square, triangular, circular, or rectangular.

[0016] Throughout this disclosure, various quantities, such as amounts, sizes, dimensions, ratios, etc., are presented in a range format. It should be understood that the description of quantities in a range format is merely for convenience and brevity, and should not be construed as an inflexible limitation on the scope of any embodiment. Thus, the description of a range should be considered to have specifically disclosed all possible subranges, as well as individual numerical values ​​within that range, unless the context clearly indicates otherwise. For example, description of a range of 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, 1.2 to 5.2, 1.25 to 5.25, etc., along with individual values ​​within that range, e.g., 1.1, 2, 2.3, 2.33, 2.35, 5, 5.9. This applies regardless of the breadth of the range. The upper and lower limits of these intervening ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also encompassed within the disclosure, unless the context clearly dictates otherwise.

[0017] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of any embodiment. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms "includes", "comprises", "including" and / or "comprising", as used herein, specify the presence of stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0018] In this specification, terms such as first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first," "second," and other numerical terms, when used herein, do not imply any order or sequence unless clearly indicated by the context. Thus, a first element, component, region, layer, or section described herein may be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0019] As used herein, ranges and amounts can be expressed as "about" a particular value or range. "About" includes the exact amount. For example, "about 5 μL" means "about 5 μL" and also means "5 μL". In general, the term "about" includes amounts that are expected to be within experimental error. The term "about" includes values ​​that are within a range of 10% less to 10% more than the value provided. For example, "about 50%" means "between 45% and 55%". Also, by way of example, "about 30" means "between 27 and 33".

[0020] Described herein in certain embodiments is a filter adapter for filtering unwanted particles during various uses, including in conjunction with negative pressure wound therapy and a syringe. In some embodiments, a filter adapter is provided having a generally tubular design. In some embodiments, a filter adapter is provided configured for in-line connection to two fluid conduits or two separate portions of a fluid conduit. In other embodiments, a filter adapter is provided having a generally tubular design sized to be placed in a fluid conduit. The filter adapter having a generally tubular design according to various embodiments described herein is characterized by a lower ratio of outer diameter to filter surface area than conventional filter adapters, and has a design that can be easily modified to provide a filter adapter with an increased filter surface area by increasing the length of the filter adapter without increasing the overall diameter of the design. As will be appreciated by those skilled in the art, an increased filter surface area allows for filtration of a larger volume of fluid and / or filtration of fluid at a higher volume rate and / or reduced pressure loss across the filter, compared to a filter having a lower surface area.

[0021] In one aspect of the disclosure, the filter adapter defines an internal fluid passageway and includes a first connector located at a first end of the filter adapter configured for connection to a first conduit for fluid delivery to the fluid passageway and a second connector located at a second end of the filter adapter configured for connection to a second conduit for fluid output from the fluid passageway, with the total flow of fluid generally in a first direction extending from the first connector to the second connector. In some examples where the filter adapter is a generally tubular filter adapter, the first direction is generally parallel to the longitudinal axis of the filter adapter. The filter adapter also includes a filter disposed within the passageway such that all fluid flowing through the passageway passes through the filter, and such that the fluid passes through the filter in a volumetric direction different from the first direction. As used herein, the term "volumetric direction" is used to refer to the direction in which the volume of fluid moves across the filter and is generally perpendicular to the filter surface at a given point on the filter. In some embodiments, the volumetric direction is not parallel to the first direction. In other embodiments, the volumetric direction is perpendicular to the first direction. In yet other embodiments, the volumetric direction forms a non-zero angle with respect to the first direction, referred to herein as an "offset angle." In some embodiments, the offset angle is at least about 15°, at least 30°, at least 45°, at least 60°, or at least 75°. Positioning the filter within the filter adapter in this manner allows fluid to pass through the filter in a direction different than the general flow direction of fluid through the adapter, allowing for design modifications that increase the filter surface area without increasing the overall dimensions, such as the diameter, of the filter adapter.

[0022] An exemplary embodiment of a filter adapter according to this aspect is illustrated in Figures 1-11. The filter adapter 100 includes a body 110 configured to engage with the housing 150 to form a fluid flow path extending from an inlet port 162 of the housing 150 located at a first end of the filter adapter 100 to an outlet port 126 of the body 120 located at a second end of the filter adapter 100. In some embodiments, the connector 120 is configured to connect to a pump unit (not shown), such as those used for negative pressure wound therapy, or to a tube (not shown) that in turn is connected to a pump unit. In Figure 1, the connector 160 is shown connected to a tube 161. The filter adapter 100 further includes a filter 190, which in this embodiment has a cylindrical shape as can be seen more clearly in Figures 5 and 6, and an indicator 195. The indicator 195 is operable to indicate a status of the filter adapter 100, such as, for example, an indication for an occlusion or an indication for dressing replacement. In some embodiments, a one-way valve (not shown) is positioned before or after the filter relative to the direction of fluid flow through filter adapter 100 .

[0023] In some embodiments, the indicator is used as a dressing change indicator or a blockage indicator. In some embodiments, the indicator is a pH level indicator. In some embodiments, the filter adapter includes multiple indicators. In some embodiments, the filter adapter includes a first indicator for dressing change and a second indicator for blockage detection. In some embodiments, one or more stripes are used for multiple indicators.

[0024] Indicators for use with the filter adapters described herein, in some embodiments, are visual indicators. In some embodiments, the indicator indicates the change by a change in the appearance of the indicator. For example, the change is a change in color. In some embodiments, the change in color is a change in the color of a line. In some embodiments, the line is horizontal, vertical, or circular. In some embodiments, the indicator comprises a symbol, letter, or number to indicate the change.

[0025] In some embodiments, the one-way valve is integrally formed in the filter adapter, such as at the location indicated by box 103. In other embodiments, the one-way valve is connected to the filter adapter 100 as a separate unit relative to the filter, either directly or through an intervening conduit, such as a tube, either upstream or downstream of the filter adapter 100 in the direction of fluid flow through the filter adapter 100. The filter adapters described herein comprise a valve in certain embodiments. In some embodiments, the valve is a one-way valve. In some embodiments, the valve is located before the filter. In some embodiments, the valve is located after the filter. The valve may comprise a check valve cartridge. In some embodiments, the check valve cartridge comprises a hydrocarbon polymer. Representative examples of hydrocarbon polymers include, but are not limited to, polyethylene, polypropylene, polystyrene, derivatives thereof, or combinations thereof. In some embodiments, the check valve cartridge comprises polystyrene. In some embodiments, the valve comprises a check valve disc. In some embodiments, the check valve disc comprises polysiloxane (also referred to herein as silicone).

[0026] The tubular filter 190 comprises a gas permeable material in some embodiments. In some embodiments, the filter is hydrophobic. In some embodiments, the filter is liquid impermeable. In some embodiments, the filter is both gas permeable and liquid impermeable. In some embodiments, the filter comprises a material that is gas permeable and liquid permeable. Representative examples of materials include, but are not limited to, polytetrafluoroethylene (PTFE), polypropylene, and polyethylene. In some embodiments, the material is microporous. In some embodiments, the material comprises pores having a diameter of at least or about 0.01 μM, 0.02 μM, 0.03 μM, 0.04 μM, 0.05 μM, 0.1 μM, 0.2 μM, 0.3 μM, 0.4 μM, 0.5 μM, 0.6 μM, 0.7 μM, 0.8 μM, 0.9 μM, 1.0 μM, or greater. In some embodiments, the material comprises pores with diameters ranging from about 0.01 μM to about 1.0 μM, about 0.02 μM to about 0.9 μM, about 0.03 μM to about 0.8 μM, about 0.04 μM to about 0.7 μM, about 0.05 to about 0.6 μM, or about 0.1 μM to about 0.4 μM, hi some embodiments, the material comprises pores with a size of about 0.2 μM.

[0027] In various embodiments, connector 120 and connector 160 may each comprise a barbed connector, a hose connector, a Luer (e.g., male or female) connector, or any other type of connector as would occur to one of ordinary skill in the art.

[0028] A cross section of the filter adapter 100 is shown in Figure 2. As shown in Figure 2, and with further reference to Figures 3 and 4, the body 110 of the filter adapter 100 includes a connector 120 and a shaft 130. The connector 120 is configured as a luer connector and includes a central mounting bore 122 defining an outlet port 126, and a hub 124, which in this embodiment is configured with threads on its inner surface to mate with a threaded collar of a male luer fitting and with ribbing on its outer surface to assist a user in gripping the connector 120. The shaft 130 is configured to be inserted into a chamber defined within a housing 150, as will be further described below. The shaft 130 defines a passageway 131 extending from an end wall 132 through the shaft 130 and through the connector 120 to the outlet port 126. Shaft 130 extends distally a short distance beyond end wall 132, thereby forming a recess 138 for receiving flange 175 of housing 150, as described further below. Shaft 130 has an outer surface 134 that defines a groove 135 and includes a bore 136 that provides fluid communication between groove 135 and passageway 131. Although groove 135 is shown in this embodiment as oriented circumferentially about shaft 130, the present disclosure contemplates other orientations of groove 135, such as, for example, spiral or helical grooves, longitudinal grooves, and mesh cut grooves.

[0029] 1, with further reference to Figures 5 and 6, filter adapter 100 further includes a filter 190 configured to be disposed over and in contact with exterior surface 134 of shaft 130. In the embodiment shown, filter 190 is cylindrical.

[0030] 2 and with further reference to FIGS. 9 and 10, filter adapter 100 also includes a housing 150 configured to connect with body 110 to define a fluid pathway from inlet port 162 to outlet port 126 of filter adapter 100. Housing 150 defines inlet port 162 and includes a connector 160 configured to connect with tube 161. Housing 150 also includes an intermediate sidewall 170 that defines an intermediate chamber within housing 150 for receiving shaft 130 of body 110 when housing 150 and body 110 are connected to one another. Intermediate sidewall 170 is sized such that an inner surface thereof is spaced from filter 190 when shaft 130 and filter 190 are disposed therein.

[0031] Housing 150 also includes flanges 175 configured to seat within recesses 138 formed in shaft 130 when housing 150 and body 110 are connected together, thereby maintaining shaft 130 centered within the intermediate chamber, thereby maintaining proper spacing to maintain a fluid flow path within filter adapter 100, as further described below. An opening 176 is defined between flanges 175, between connector 160 and the intermediate chamber.

[0032] The housing 150 also includes an outer sidewall 180 configured to engage the body 110 such that the outer sidewall 180 is configured to provide a fluid collection space 181 between the outer sidewall 180 and the shaft 130 of the body 110. In the embodiment shown, the housing also includes a circumferential collar 185 that extends into the fluid collection space and defines a slot for retaining an indicator 195 within the fluid collection space, as seen most clearly in Figures 1 and 2. In other embodiments not shown, the collar 185 and indicator 195 are not present.

[0033] 2, arrows 199 indicate the fluid flow path entering inlet port 162, through filter adapter 100, and exiting through outlet port 126. More specifically, arrows 199 indicate the direction of fluid flow in various regions of filter adapter 100, from the inlet port, through connector 160, through an opening between connector 160 and the intermediate chamber, where the fluid flow is redirected laterally through flange 175 toward outer surface 134 of shaft 130, where the fluid flow path is then redirected again by intermediate sidewall 170 of housing 150, and flows toward the fluid collection space and indicator 195 of this embodiment. Within the intermediate cavity and fluid collection space, the fluid flow path is redirected again toward passage 131, travels through filter 190 into groove 135, then through hole 136 into passage 131, where it is redirected again toward outlet port 126.

[0034] In the embodiment shown, fluid flow is achieved in the direction of arrow 199 by applying a pressure gradient across filter adapter 100 sufficient to force fluid through filter 190. Pressure can be applied by applying a positive pressure to the inlet port side of filter adapter 100 or a negative pressure (i.e., suction) to the outlet port side of filter adapter 100. Additionally, the construction of filter adapter 100 allows for fluid flow in the reverse direction as well, with outlet port 126 acting as the inlet port and inlet port 162 acting as the outlet port. When filter adapter 100 or a variation thereof is used in this opposite direction, indicator 195 and collar 185 can be omitted. Of course, in embodiments in which indicator 195 is omitted, a user may employ a separate indicator unit by placing the indicator upstream of the filter adapter (i.e., between the filter adapter and the wound dressing or "pre-filter").

[0035] As will be appreciated by those skilled in the art, an adapter having similar features to adapter 100 can be configured to significantly increase the surface area of ​​filter 190 without increasing the outer diameter of the adapter, simply by increasing the length of adapter 100 and increasing the length of filter 190. Lengthening filter 190 can increase the surface area of ​​filter 190 available for fluid passage without increasing the outer profile of the filter adapter.

[0036] Another exemplary embodiment of a filter adapter according to this aspect of the disclosure is illustrated in Figures 12-14. Filter adapter 200 differs from filter adapter 100 in that filter adapter 200 does not include a housing, does not include a connector, and is not configured for attachment to a conduit as filter adapter 100 does. Rather, filter adapter 200 is configured to be disposed within the lumen of a conduit to filter fluid flowing therethrough. Filter adapter 200 includes a body 210 configured to frictionally engage the lumen wall of a conduit into which filter adapter 200 is inserted.

[0037] Body 210 of filter adapter 200 includes seal 220 and shaft 230. Seal 220 has an outer diameter dimension that approximates the lumen dimension of a conduit in which filter adapter 200 is to be used and defines an outlet port 226. Optionally, seal 220 may include circumferential ribs (not shown) on its outer surface to assist in frictional engagement of seal 220 with the lumen. Shaft 230 of body 210 has an outer diameter dimension that is smaller than the lumen dimension of a conduit in which filter adapter 200 is to be used. Shaft 230 defines a passageway 231 that extends through shaft 230 from end wall 232, through seal 220, and to outlet port 226. Shaft 230 has an outer surface 234 that defines a groove 235 similar to groove 135 of filter adapter 100, and includes a bore 236 that provides fluid communication between groove 235 and passageway 231.

[0038] The filter adapter 200 further includes a filter 290 configured to be disposed on and contact the outer surface 234 of the shaft 230. In the embodiment shown, the filter 290 is cylindrical. In one embodiment (not shown), the body 210 also includes a flange 275 extending laterally from the distal end 237 of the shaft 230, which serves to hold the filter 290 in place relative to the shaft 230 and to keep the end 237 of the shaft 230 centered within the lumen into which the filter adapter is inserted, thereby providing the proper spacing to maintain a fluid flow path between the filter 290 and the lumen wall.

[0039] Fluid flow within the lumen is in the direction indicated by arrow 299. When the fluid reaches filter adapter 200, it passes between filter 290 and the lumen wall toward seal 220. Within the space between the filter and the lumen wall, the fluid flow path is redirected toward passageway 231, passes through filter 290, enters groove 235, and then travels through hole 236 into passageway 231, where it is redirected again toward outlet port 226.

[0040] In the embodiment shown, fluid flow is achieved in the direction of arrow 299 by applying a pressure gradient across filter adapter 200 sufficient to force fluid through filter 290. Pressure can be applied by applying a positive pressure on the upstream side of filter adapter 200 or by applying a negative pressure (i.e., suction) on the downstream side of filter adapter 200. Additionally, the structure of filter adapter 200 allows fluid flow in the opposite direction to that described above to work as well, where outlet port 226 acts as an inlet port and fluid flows into inlet port 226, through passageway 231, through hole 236 into groove 235, and then through filter 290 before continuing through the lumen in the direction opposite to arrow 299.

[0041] As will be appreciated by those skilled in the art, an adapter having similar features to adapter 200 may be constructed to significantly increase the surface area of ​​filter 190 without increasing the outer diameter of the adapter, simply by increasing the length of shaft 230 and increasing the length of filter 290. By lengthening filter 290 and shaft 230, the surface area of ​​filter 290 available for fluid passage can be increased without increasing the outer profile of the filter adapter.

[0042] Another exemplary embodiment of a filter adapter according to this aspect of the disclosure is illustrated in Figures 15 and 16. Filter adapter 300 differs from filter adapter 100 in that filter adapter 300 does not include a cylindrical filter as used in filter adapter 100. Rather, filter adapter 300 includes a generally planar filter block 390. Filter adapter 300 includes a body 310 including a connector 320 defining an outlet port 326, a connector 360 defining an inlet port 362, and filter retaining brackets 330, 331 operable to hold planar filter block 390 in a longitudinal position separating first side passage 332 from second side passage 333. First side passage 332 opens directly into inlet port 362. Second side passage 331 opens directly into outlet port 326.

[0043] Connector 320 is configured as a luer connector and includes a central mounting bore 322, which defines an exit port 326. Connector 360 defines an inlet port 362 and is configured to connect to a tube. With reference to FIG. 16 , arrows 399 indicate a fluid flow path from inlet port 362, through filter adapter 300, and out through exit port 326. More specifically, arrows 399 indicate the direction of fluid flow in various regions of filter adapter 300 from inlet port 362, through connector 360, and into first side passage 332, where the direction of fluid flow changes through filter 390 to second side passage 333, where the direction of fluid flow is again changed toward exit port 326.

[0044] In the embodiment shown, fluid flow is achieved in the direction of arrow 399 by applying a pressure gradient across filter adapter 300 sufficient to force fluid through filter 390. Pressure can be applied by applying a positive pressure to the inlet port side of filter adapter 300 or a negative pressure (i.e., suction) to the outlet port side of filter adapter 300. Additionally, the structure of filter adapter 300 allows fluid flow in the reverse direction to work as well, with outlet port 326 acting as the inlet port and inlet port 362 acting as the outlet port.

[0045] As will be appreciated by those skilled in the art, an adapter having similar features to adapter 300 can be constructed to significantly increase the surface area of ​​filter 390 without increasing the outer diameter of the adapter, simply by increasing the length of adapter 300 and increasing the length of filter 390. Lengthening filter 390 can increase the surface area of ​​filter 390 available for fluid passage without increasing the outer profile of the filter adapter.

[0046] In some embodiments, the body and housing components of the filter adapters 100, 200, and 300 comprise polymeric materials. Representative examples of polymers include, but are not limited to, polyurethane, ionomer, polycarbonate, polysulfone, acrylic, polyamide, acrylonitrile-butadiene-styrene terpolymer, polyethylene terephthalate, polyoxymethylene, acrylonitrile, styrene acrylonitrile, styrene butadiene rubber, polyaryletherketone, or polyetherketone. In some embodiments, the filter adapter comprises an acrylic polymer. In some embodiments, the filter adapter comprises acrylonitrile-butadiene-styrene. In some embodiments, the filter adapter comprises glass, fused silica, silicon, plastic (e.g., polytetrafluoroethylene, polypropylene, polystyrene, polycarbonate, polymethylmethacrylate, and blends thereof), or metal. In some embodiments, the filter connector comprises polypropylene, polycarbonate, nylon, or PVDF material.

[0047] In some embodiments, the filter has a size of at least or about 10 square millimeters (mm 2 ), 40mm 2 , 90mm 2 , 150mm 2 , 245mm 2 , 350mm 2 , 480mm 2 , 625mm 2 , 790mm 2 , 980mm 2 Or 1960mm 2 In some embodiments, the surface area of ​​the filter is about 10 mm 2 ~Approx. 1960mm 2 , approx. 40mm 2 ~ approx. 980mm 2 , or about 90 mm 2 ~Approx. 625mm 2In some embodiments, the filter adapter has a length of at least or about 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, or 50 mm. In some embodiments, the length of the filter adapter is in the range of about 10 mm to about 50 mm, about 15 mm to about 40 mm, or about 20 mm to about 30 mm. In some embodiments, the outer diameter of the filter adapter is at least or about 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 89 mm, or 10 mm. In some embodiments, the outer diameter of the filter adapter is in the range of about 3 mm to about 10 mm, about 4 mm to about 9 mm, or about 4 mm to about 8 mm. In some embodiments, the outer diameter of the filter is about 25 mm. In some embodiments, the filter adapter has a filter surface area (mm) to outer diameter (mm). 2 ) is at least or about 2:1, 5:1, 10:1, 15:1, 20:1, or 25:1. In some embodiments, the ratio of surface area (mm) to outer diameter (mm 2 ) is within the range of about 2:1 to about 50:1, about 5:1 to about 25:1, or about 5:1 to about 20:1.

[0048] In another aspect of the present disclosure, a filter adapter is provided that includes a body defining an internal fluid passageway and a filter material including a gelling absorbent material contained within the passageway. The gelling absorbent material, when in a dry state, can allow the passage of air, vapor, and other gases upon application of a pressure gradient across the filter adapter, thereby absorbing aqueous fluids, such as wound exudate, upon contact. Upon contact with aqueous fluids, the gelling absorbent material transforms into a gel and thereafter blocks the passage of air, vapor, and other gases through the body of the filter adapter. In various embodiments, the gelling absorbent material may be a nonwoven, knitted, or tightly woven formation. The gelling absorbent material may expand upon absorption of aqueous fluids, such as wound exudate or other fluids generated from a wound site. When the gelling absorbent material blocks the passage of air, vapor, and other gases through the body of the filter adapter, the blockage creates a pressure drop in the pump, which is indicative of a need for a dressing change (i.e., wound exudate has reached the filter adapter). In some embodiments, the gelling absorbent material also includes an indicator that functions as an occlusion indicator or a dressing change indicator, hi some embodiments, the indicator comprises a symbol, letter, number, or color to indicate a change.

[0049] In some embodiments, the gelling absorbent material comprises gel-forming fibers, gel-forming filaments, or gel-forming agents. In some embodiments, the gel-forming fibers or filaments are chemically modified cellulose, alginate, or carboxymethylcellulose, or combinations thereof. In some embodiments, the gel-forming fibers are carboxymethylcellulose. The gelling absorbent material can also include other absorbent materials, such as, for example, polyacrylates, polyacrylate fibers, bicomponent superabsorbent fibers, airlaid nonwovens, needlefelt nonwovens, thermally bonded nonwovens, and foams.

[0050] Some formulations of gelling absorbent materials contain alginate to enhance the absorbent capacity. The active surface of the absorbent layer can be coated with a cross-linked adhesive material that includes a dispersion of gelatin, pectin and / or carboxymethylcellulose along with other polymers. When the polysaccharides and other polymers come into contact with aqueous fluids, they absorb water and swell, forming a gel. The gel formed as a result of water absorption is retained within the body of the filter adapter.

[0051] The gelling absorbent material preferably comprises gel-forming fibres. The gel-forming fibres may be of a type that retains its structural integrity when absorbing exudates, or of a type that loses its fibrous form and becomes a structureless gel. The gel-forming fibres are preferably spun sodium carboxymethylcellulose fibres, chemically modified cellulose fibres, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres or fibres derived from other polysaccharide fibres or gums. The gel-forming fibres are preferably sodium carboxymethylcellulose fibres, chemically modified cellulose fibres, alkylsulfonic acid modified cellulose fibres as described in WO2012 / 061225, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres or fibres derived from other polysaccharide fibres or gums. The gel-forming fibres are preferably chemically modified cellulose fibres in woven form, in particular carboxymethyl cellulose fibres as described in PCT WO00 / 01425 to Azko Nobel UK Ltd. The cellulose fibers preferably have a degree of substitution of at least 0.05 carboxymethyl groups per glucose unit. In another embodiment, the cellulose fibers have a degree of substitution of about 0.12 to about 0.35 as measured by IR spectroscopy (as defined in WO00 / 01425). In another embodiment, the cellulose fibers have a degree of substitution of about 0.20 to about 0.30 and are produced by carboxymethylating woven or nonwoven cellulose fibers to increase absorbency. The gel-forming fibers preferably have an absorbency of at least 2 grams of 0.9% saline per gram of fiber (measured by the free swell absorbency method). Preferably, the gel-forming fibers have an absorbency of at least 10 g / g as measured by the free swell absorbency method, more preferably between 15 g / g and 25 g / g.

[0052] Gelling absorbent materials may be prepared according to the disclosure of WO 93 / 12275 which describes the preparation of a variety of absorbent carboxymethyl cellulose products capable of absorbing many times their own weight in water.

[0053] Carboxymethylation can be accomplished, for example, by sequentially or simultaneously treating the cellulosic material with a strong alkali, such as sodium hydroxide, and monochloroacetic acid or a salt thereof. Suitable reaction conditions will depend on the composition of the textile and the degree of carboxymethylation required, and will be readily apparent to those skilled in the art. They may be the same as or similar to those described in WO93 / 12275, WO94 / 16746 or WO00 / 01425. Desirably, the carboxymethylation is carried out in the presence of industrial methanol methylated spirits (IMS), which is also used in the subsequent washing steps as a cleaning and sterilizing agent, preferably together with water.

[0054] In some embodiments, the gelling absorbent material comprises carboxymethyl cellulose fibers formed into a woven fabric. In other embodiments, the gelling absorbent material comprises two or more layers of a woven fabric comprising carboxymethyl cellulose fibers. In some embodiments, the gelling absorbent material comprises compressed carboxymethyl cellulose. In some embodiments, the compressed carboxymethyl cellulose has a density of about 10 to about 70 kg / cm. 3 Various degrees of compression, and therefore various densities, are contemplated and may be determined based on the size of a given filter adapter and the fluid flow rate desired for the filter adapter.

[0055] 17, filter adapter 400 includes a body 410 that includes a connector 420 that defines an inlet port 426 and a connector 460 that defines an outlet port 462, and defines a chamber 411 operable to hold a filter 490 comprising a gelling absorbent material. Body 410 also defines openings 412, 413 that fluidly connect chamber 411 to inlet port 426 and outlet port 462, respectively. Arrow 499 indicates a fluid flow path entering inlet port 426, through filter adapter 400, and exiting through outlet port 362. More specifically, arrow 499 indicates the direction of fluid flow from inlet port 426, through connector 420, through opening 412, and into chamber 411, where the fluid flow passes through filter 490 and then through opening 413 into connector 460 and toward outlet port 462. In the embodiment shown, fluid flow is accomplished in the direction of arrow 499 by application of a pressure gradient across filter adapter 400 sufficient to force fluid through filter 490. Pressure can be applied by applying a positive pressure to the inlet port side of filter adapter 400 or a negative pressure (i.e., suction) to the outlet port side of filter adapter 400. Additionally, the construction of filter adapter 400 allows fluid flow in the opposite direction as well, with outlet port 462 acting as the inlet port and inlet port 426 acting as the outlet port. As with other embodiments described herein, first connector 420 is configured to connect to a first conduit for fluid delivery to filter adapter 400 and second connector 460 is configured to connect to a second conduit for fluid output from filter adapter 400.

[0056] As will be appreciated by those skilled in the art, an adapter having similar features to adapter 400 can be configured to significantly increase the capacity of filter 490 without increasing the outer diameter of the adapter, simply by increasing the length of adapter 400 and increasing the length of filter 490. Lengthening filter 490 increases the volume of filter 490 available for fluid passage without increasing the outer profile of the filter adapter.

[0057] In some embodiments, the outer dimension of filter adapter 100, generally defined by the outer dimension of hub 124 and outer sidewall 180, filter adapter 200, generally defined by the outer dimension of seal 220, filter adapter 300, generally defined by the outer dimension of body 310, and / or filter adapter 400, generally defined by the outer dimension of body 410, is 25 mm or less. In some embodiments, the outer dimension of the filter adapter is at least or greater than about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 20 mm, 25 mm, or 25 mm. In some embodiments, the outer dimension of the filter adapter is about 11 mm. In some embodiments, the length of the filter adapter is 30 mm or less. In some embodiments, the length of the filter adapter is at least or about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or greater than 50 mm, hi some embodiments, the length of the filter adapter is about 25 mm.

[0058] Another filter adapter embodiment including a filter made of gelling absorbent material is illustrated in Figures 18-20. In filter adapter 500, also referred to as spiral filter 500, chamber 511 holding gelling absorbent material filter 590 is in the form of a spiral tube that defines a spiral flow path. In alternative embodiments, chamber 511 can be formed into alternatively different shapes.

[0059] The filter adapter 500 can be manufactured by assembling four components, for example, as shown conceptually in FIG. 19. The bottom layer 520 includes weld traces 524 to define a central opening 522 and form the chamber 511. The top layer 530 includes weld traces 534 having a shape and location corresponding to the weld traces 524 on the bottom layer 520. The filter material 590 is shaped such that when the bottom layer 520, the filter material 590 and the top layer 530 are pressed together, a first end 591 of the filter material 590 is adjacent the central opening 522 and the filter material 590 spirals outwardly between the weld traces 524, 534 to a point where a second end 592 of the filter material 590 is adjacent the first end 541 of the conduit 540. The filter material 590 can be formed into the desired shape, for example, by die punching the desired shape from a layer of gelling absorbent material. When the bottom layer 520, fabric material 590, conduit 540 and top layer 530 are positioned as described, the bond traces 524, 534 are fused together by heat sealing or welding, such as, for example, radio frequency or laser welding, to achieve a filter adapter 500 that defines a chamber 511 formed in a spiral path with the filter 590 contained therein. In one embodiment, the filter adapter 500 also includes an indicator 550 located in the center of the spiral path adjacent the central opening 522. In some embodiments, the indicator is an occlusion indicator or a dressing change indicator. In some embodiments, the indicator comprises a symbol, letter, number, or color to indicate a change.

[0060] In some embodiments, the filter adapter 500 is mounted directly onto a foam dressing or other negative pressure wound treatment dressing, as shown in Figure 20. In this embodiment, the central opening 522 is connected to an opening or port in a cover layer (not shown) of the dressing that opens to the dressing / wound environment, such that upon connection of the second end 542 of the conduit 540 to a source of negative pressure, such as a vacuum pump (not shown), negative pressure is transferred through the conduit 540, the chamber 511 and the central opening 522 to the dressing / wound environment.

[0061] As will be appreciated by those skilled in the art, an adapter having similar features to adapter 500 can be configured to significantly increase the capacity of filter 590 without increasing the outer diameter of the adapter, simply by increasing the length of filter 590 and, if desired, increasing the number of helices in filter adapter 500. By lengthening filter 590, the volume of filter 590 available for the passage of fluid can be increased without increasing the outer profile of the filter adapter.

[0062] Using a Filter Adapter

[0063] The filter adapters described herein may be used in a variety of applications including negative pressure wound therapy, wound dressings, and syringe filters. In some embodiments, the filter adapter is used in negative pressure wound therapy. For example, the filter adapter is connected to a source of negative pressure, such as a vacuum pump, for use in negative pressure wound therapy. In some embodiments, the filter adapter includes a tube connected to the dressing, or in some cases, the filter adapter may be connected directly to the dressing, such as, for example, the types of filter adapters shown in FIGS. 18-20.

[0064] While a number of separate embodiments have been described, aspects of each embodiment may not be specific to that embodiment only, and it is specifically contemplated that features of an embodiment may be combined with features of other embodiments. As will be understood from the description herein and the associated figures, a wide variety of aspects and embodiments are contemplated by the present disclosure, including, but not limited to, the following listed aspects and embodiments: (i) a filter adapter including a body defining an internal passageway disposed between an inlet and an outlet, the passageway configured to permit passage of a fluid in a first direction defined by the inlet and the outlet; and (ii) a filter disposed within the passageway and oriented to define a volumetric direction different from the first direction.

[0065] In any other embodiment filter adapter disclosed herein, the volumetric direction is perpendicular to the first direction.

[0066] In any other embodiment of the filter adapter disclosed herein, the volumetric direction and the first direction are offset by an angle of at least 15°.

[0067] In any other embodiment of the filter adapter disclosed herein, the filter adapter has a tubular shape and an outer diameter, and the filter has a surface area that is independent of the outer diameter.

[0068] In any other embodiment of the filter adapter disclosed herein, the outer diameter is between about 3 mm and about 15 mm.

[0069] In any other embodiment of the filter adapter disclosed herein, the filter is cylindrical.

[0070] In any other embodiment of the filter adapter disclosed herein, the filter is planar.

[0071] In any other embodiment of the filter adapter disclosed herein, the filter lies in a plane that is not perpendicular to the first direction.

[0072] In any other embodiment of the filter adapter disclosed herein, the filter lies in a plane that forms an angle with the first direction, the angle being less than 45°.

[0073] In any other embodiment of the filter adapter disclosed herein, the body includes a first connector at the inlet and a second connector at the outlet.

[0074] In any other embodiment of the filter adapter disclosed herein, the first connector and the second connector each comprise a barbed connector, a hose connector, or a luer connector.

[0075] The filter adapter according to any other embodiment disclosed herein further includes an indicator located within the interior passageway.

[0076] In any other embodiment of the filter adapter disclosed herein, the indicator detects a blockage or detects the need for a dressing change.

[0077] In any other embodiment of the filter adapter disclosed herein, the indicator sensor comprises a change in a symbol, letter, number, or color.

[0078] In any other embodiment of the filter adapter disclosed herein, the filter comprises a gas permeable material.

[0079] In any other embodiment of the filter adapter disclosed herein, the filter comprises a liquid impermeable material.

[0080] In any other embodiment filter adapter disclosed herein, the filter is gas permeable and liquid impermeable.

[0081] In any other embodiment filter adapter disclosed herein, the filter is hydrophobic.

[0082] A filter adapter comprising: (i) a body defining an internal passageway disposed between an inlet and an outlet; and (ii) a filter disposed within the passageway, the filter comprising a gelling absorbent material that is gas permeable in a dry state and converts to a gel upon contact with an aqueous fluid.

[0083] In any other embodiment of the filter adapter disclosed herein, the gelling absorbent material includes gel-forming fibers.

[0084] In any other embodiment of the filter adapter disclosed herein, the gelling absorbent material includes compressed gel-forming fibers.

[0085] In any other embodiment of the filter adapter disclosed herein, the compressed gel-forming fibers have a density of about 10 to about 70 kg / cm 3 It is.

[0086] In any other embodiment of the filter adapter disclosed herein, the interior passage comprises a helical path.

[0087] While embodiments of the present disclosure have been shown and described herein, it will be understood by those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the present disclosure. It should be understood that various alternatives to the embodiments of the present invention described herein may be employed in implementing the present invention. It is intended that the following claims define the scope of the present invention, and that methods and structures within the scope of these claims, and their equivalents, be covered thereby.

Claims

1. a body and a housing, together defining an internal passageway disposed between an inlet and an outlet, the passageway configured to permit fluid to pass therethrough in a first direction defined by the inlet and the outlet; a filter disposed within the passageway and oriented to define a volumetric direction different from the first direction; and an indicator located within the interior passage; Equipped with A filter adapter, wherein the housing has the inlet and the body has the outlet, the body and the housing being removably coupled to one another.

2. the volumetric direction is perpendicular to the first direction; The filter adapter of claim 1 .

3. the volumetric direction and the first direction are offset by an angle of at least 15°; 3. A filter adapter according to claim 1 or 2.

4. The filter adapter has a tubular shape and has an outer diameter. The filter has a surface area independent of the outer diameter. A filter adapter according to any one of claims 1 to 3.

5. The outer diameter is about 3 mm to about 15 mm. The filter adapter of claim 4.

6. The filter is cylindrical. A filter adapter according to any one of claims 1 to 5.

7. The filter adapter includes a first connector at the inlet and a second connector at the outlet. A filter adapter according to any one of claims 1 to 6.

8. Each of the first connector and the second connector comprises a barbed connector, a hose connector, or a luer connector.

8. The filter adapter of claim 7.

9. The indicator detects an obstruction or detects the need for a dressing change. A filter adapter according to any one of claims 1 to 8.

10. The indicator comprises a change in a symbol, letter, number, or color. A filter adapter according to any one of claims 1 to 9.

11. The filter comprises a gas permeable material. A filter adapter according to any one of claims 1 to 10.

12. The filter comprises a liquid impermeable material. A filter adapter according to any one of claims 1 to 11.

13. The filter is gas permeable and liquid impermeable. A filter adapter according to any one of claims 1 to 12.

14. the filter is hydrophobic; A filter adapter according to any one of claims 1 to 13.

15. The filter comprising a gelling absorbent material that is gas permeable in a dry state and that converts to a gel upon contact with an aqueous fluid. A filter adapter according to any one of claims 1 to 14.

16. The gelling absorbent material comprises gel-forming fibers.

16. The filter adapter of claim 15.

17. The gelling absorbent material comprises compressed gel-forming fibers.

17. A filter adapter according to claim 15 or 16.

18. The compressed gel-forming fiber has a density of about 10 to about 70 kg / cm ３ That is, 20. The filter adapter of claim 17.

19. the internal passageway comprises a helical path; 19. A filter adapter according to any one of claims 1 to 18.

20. The filter is planar.

20. A filter adapter according to any one of claims 1 to 19.

21. the filter exists on a plane that is not perpendicular to the first direction.

21. The filter adapter of claim 20.

22. the filter lies in a plane that forms an angle with the first direction, the angle being less than 45°.

22. A filter adapter according to claim 20 or 21.

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