Reduced Pressure Therapy Treatment System

Abstract

The treatment system includes a dressing having a reduced pressure layer and an occlusion layer that secures the dressing around the treatment site and defines a treatment chamber within which the reduced pressure layer is located. Operation of an evacuation device fluidly coupled to the chamber compresses the reduced pressure layer away from the tissue site, resulting in a tensile force being applied to the treatment site. This reduced pressure at the tissue site can increase perfusion of blood and other fluids and advantageously reduce swelling at the treatment site. To increase the degree of lift at the treatment site, the reduced pressure layer is advantageously constructed to provide a parallel plate effect during use of the treatment system. For example, the reduced pressure layer is constructed with a center of rigidity located closer to the outward-facing surface of the reduced pressure layer than to the tissue-facing surface of the reduced pressure layer.

Description

Background Art

[0001] Cross - reference to Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 929,215, filed November 1, 2019, and U.S. Provisional Patent Application No. 62 / 955,534, filed December 31, 2019, which are hereby incorporated by reference in their entirety.

[0002] Swelling associated with trauma or certain pathologies (e.g., lymphedema) can cause various medical complications. For example, swelling can cause discomfort and pain, can limit the range of motion, or otherwise negatively affect the patient's quality of life. Swelling can also limit the ability of a healthcare provider to medically image, visualize, and access underlying tissues, or otherwise interfere with the patient's treatment, thus presenting an impediment to the patient's healing and recovery. In some situations, swelling can even result in more severe outcomes such as atrophy of the surrounding muscle tissue.

[0003] It would be advantageous to provide a durable, reusable treatment system that can be readily applied to a tissue site, can be cleaned (or otherwise sterilized) between uses, and can reliably and repeatedly operate to provide a decompression therapy that increases blood perfusion and lymphatic flow at the tissue site to reduce swelling.

Summary of the Invention

[0004] According to one embodiment of the present disclosure, an apparatus for applying a lifting force to a patient's tissue site includes an occlusion layer, a decompression layer, and a connector. The occlusion layer is configured to be sealed to the patient around the tissue site so as to define a substantially airtight chamber. The decompression layer is disposed within the chamber defined by the occlusion layer, in a location proximate to the tissue site. The decompression layer includes a compressible fabric that defines one or more flow paths therethrough. The connector is provided along the occlusion layer and is configured to fluidly couple the chamber to a vacuum source. When the vacuum source operates, the decompression layer is configured to compress in a direction away from the tissue site.

[0005] According to some embodiments, when sealed to the patient, the occlusion layer extends at least 360 degrees around a limb (or other anatomical structure) that defines the tissue site, and the decompression layer compresses radially outwardly during operation of the vacuum source. In other embodiments, when sealed to the patient, the occlusion layer extends less than 360 degrees around a limb (or other anatomical structure) that defines the tissue site, and the decompression layer compresses in an upward direction during operation of the vacuum source.

[0006] In some embodiments, the decompression layer is formed from a macromesh material (e.g., macromesh fabric). The macromesh material optionally includes an upper layer, a lower layer, and a plurality of filaments extending between and connecting the upper layer and the lower layer. The filaments are flexible such that the distance between the upper layer and the lower layer before operation of the vacuum source is greater than the distance between the upper layer and the lower layer during operation of the vacuum source.

[0007] In various embodiments, the upper layer extends substantially continuously with respect to the lower layer. The upper layer has at least one of higher rigidity and higher density than the lower layer.

[0008] The macro-mesh material optionally further includes a first intermediate layer disposed between the upper layer and the lower layer. The first intermediate layer has at least one of higher rigidity and higher density than the lower layer. In some embodiments, the first intermediate layer is formed of the same material as the upper layer. A plurality of filaments extend between the first intermediate layer and at least one of the lower layer and the upper layer.

[0009] The macro-mesh material optionally further includes a second intermediate layer disposed between the upper layer and the first intermediate layer. The second intermediate layer has at least one of lower rigidity and lower density than the first intermediate layer.

[0010] In other embodiments, the macro-mesh material optionally further includes a second intermediate layer disposed between the lower layer and the first intermediate layer. The second intermediate layer has at least one of lower rigidity and lower density than the first intermediate layer. In various embodiments, the second intermediate layer is formed of the same material as the lower layer.

[0011] The center of mass of the decompression layer may be located at a height along the decompression layer that is closer to the upper surface of the decompression layer than to the lower surface of the decompression layer.

[0012] An optional interface layer is located below the lower surface of the decompression layer. The interface layer contacts the skin surrounding the tissue site when the occlusion layer is sealed to the patient. The interface layer may include a non-woven breathable fabric. The interface layer may be a separate structure provided separately from the decompression layer. The interface layer is optionally selectively releasably attached to at least one of the decompression layer and the occlusion layer. In some embodiments, the interface layer is attached to the decompression layer along the lower surface of the decompression layer.

[0013] In some embodiments, the occlusion layer and the decompression layer are attached to each other so as to define an annular structure including at least a first open end. The annular structure has a size for attachment to one of the patient's knee, ankle, leg, arm, or hand. In some embodiments, the annular structure optionally further defines a sleeve-like structure including a second open end.

[0014] According to one embodiment of the present disclosure, an apparatus for increasing at least one of blood perfusion and lymph flow at a tissue site includes a circumferentially extending occlusion layer, a decompression layer, and a connector. The occlusion layer is configured to be sealed to a patient around the tissue site so as to define a substantially airtight chamber. The decompression layer has a lower surface configured to be disposed adjacent to the tissue site within the chamber defined by the occlusion layer. The connector is configured to fluidly couple the chamber to a vacuum source. Upon operation of the vacuum source, the decompression layer is configured to compress in a direction away from the tissue site.

[0015] The occlusion layer optionally includes one of a boot-like configuration or a hand-like configuration. The shape and size of the decompression layer can be similar to the occlusion layer configuration. The size of the decompression layer is smaller than the size of the occlusion layer such that the decompression layer is concentric with respect to the occlusion layer. In some embodiments, the occlusion layer includes at least one of a zipper and a gasket.

[0016] In some embodiments, the decompression layer includes a first mesh layer vertically offset from a second mesh layer by a flexible layer. The first mesh layer is located on the side opposite the occlusion layer, and the second mesh layer is located on the side opposite the tissue site. The second mesh layer can move radially outwardly toward the first mesh layer during operation of the vacuum source. The first mesh layer can have a higher density than the second mesh layer.

[0017] According to one embodiment of the present disclosure, a method for providing negative pressure therapy includes attaching a dressing adjacent to intact skin extending over a treatment site. The dressing includes an occlusive layer configured to define a substantially airtight chamber between the patient's skin and the lower surface of the occlusive layer, and a compressible negative pressure layer including a plurality of fluid flow paths extending therethrough. An air displacement device fluidly coupled to the chamber operates to exhaust air from the chamber. The exhaust of air from the chamber compresses the negative pressure layer in a direction away from the tissue site. The compression of the negative pressure layer in the direction away from the tissue site is configured to pull the intact skin in an outward direction relative to the treatment site.

[0018] The negative pressure layer optionally includes a first mesh layer facing the occlusive layer and a second mesh layer facing the treatment site. The second layer is configured to move relative to the first layer in a direction opposite to the treatment site upon exhaustion of air from the chamber. In some embodiments, the first layer has at least one of a greater density and a greater rigidity than the second layer.

[0019] An optional interface layer can be attached adjacent to intact skin extending over the treatment site. In some embodiments, the occlusive layer and the negative pressure layer are attached to the patient's skin after attaching the interface layer to the patient. The occlusive layer can be attached to the patient after attaching the negative pressure layer to the patient.

[0020] The treatment site optionally corresponds to a location for at least one of a limb fracture, contused tissue, and bruised tissue. The exhaust of air from the chamber reduces swelling at the treatment site from a first degree of swelling to a second degree of swelling. In some embodiments, the treatment site undergoes surgical treatment after the reduction of swelling at the treatment site from the first degree of swelling to a degree of swelling equal to or less than the second degree of swelling. The reduction of swelling from the first degree of swelling to the second degree of swelling occurs 3 to 7 days after the initial operation of the air displacement device for exhausting air from the chamber.

Brief Description of the Drawings

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[0037] Before referring to the drawings that illustrate certain exemplary embodiments in detail, it is to be understood that the present disclosure is not limited to the details or methods described in the description or shown in the drawings. Also, it is to be understood that the terms used herein are for the purpose of description only and should not be construed as limiting.

[0038] Generally referring to the figures, various embodiments will be described of a negative pressure therapy treatment system for applying a vacuum to intact skin that extends over or surrounds various types of treatment tissue sites (e.g., bone tissue, adipose tissue, muscle tissue, nerve tissue, skin tissue, vascular tissue, connective tissue, cartilage, tendon, ligament, etc.). The application of the vacuum to the intact skin provided by the treatment system applies a tensile (e.g., lifting) force to the intact skin, which reduces the pressure on the treatment tissue site, thereby increasing blood perfusion and perfusion of other fluids (e.g., lymphatic flow) at the treatment tissue site.

[0039] The reduction in pressure of the treatment tissue site resulting from the operation of the treatment system can advantageously be used to reduce swelling at the tissue site. The treatment system is configured for use in both medical and non-medical situations and can be used to treat swelling resulting from a variety of different conditions. For example, the treatment system can be used by a patient in a home setting to treat swelling resulting from an injury, overuse, an underlying medical condition (e.g., lymphedema), etc.

[0040] In yet other embodiments, the treatment system may also be used in a medical situation, for example, to reduce swelling during a patient's pre-operative and / or post-operative care. For example, reducing swelling at a treatment site prior to surgery (e.g., caused by a fracture, edema, tissue contusion, tissue bruise, etc.) can advantageously facilitate access to the underlying tissue at the target surgical site, reduce surgical time, and / or improve the outcome of the surgical treatment. Use of the treatment system according to any of the embodiments described herein prior to surgical treatment can advantageously reduce the time required to reduce the swelling at the target surgical site to an acceptable level of swelling compared to the time required to reduce the swelling using conventional methods of treating swelling. For example, use of the treatment system can reduce the swelling to an acceptable level of swelling within 3 to 7 days from the start of treatment using the treatment system.

[0041] In addition to the use of the treatment system to reduce swelling, the negative pressure therapy provided by the treatment system can also advantageously be used in the treatment of various other medical conditions or diseases. As one non-limiting example, the treatment system can be used for the acute treatment of pain and / or inflammation (e.g., resulting from a contusion or other stress at a tissue site). In yet other situations, the treatment system can be used to increase blood perfusion and / or lymphatic flow at the treatment tissue site to minimize the effects of overexertion (e.g., after a sports training session or other strenuous activity).

[0042] Referring to FIG. 1, a treatment system 10 generally includes a dressing 100 configured to be attached to a patient at a location surrounding a treatment tissue site, and an exhaust device 200 (e.g., a vacuum source, a negative pressure pump, etc.) configured to provide a negative pressure source to a treatment chamber defined between the dressing 100 and the treatment tissue site. During operation of the exhaust device 200, a treatment chamber defined between the patient's intact skin and the dressing 100 functions as a decompression chamber, and in the decompression chamber, when air is exhausted from the treatment chamber, the skin and underlying tissue are subjected to an outward tensile (e.g., lifting) force (represented typically by the arrows in FIG. 2). An optional controller coupled to one or both of the dressing 100 and the exhaust device 200 may control the application of negative pressure therapy to the treatment site using the treatment system 10.

[0043] As shown by an embodiment of the treatment system 10 of FIG. 1, the dressing 100 and the exhaust device 200 are optionally provided as separate, individually located components that are remotely located from each other. In such an embodiment, the exhaust device 200 is fluidly and sealingly coupled to the treatment chamber via an external tube 205. An optional connector port 90 sealingly attached around an opening 111 extending through the dressing 100 may facilitate the fluid connection between the treatment chamber and the exhaust device 200. In other embodiments (e.g., embodiments where the dressing 100 is configured to be wrapped around the patient), other connector port structures and / or configurations may be used to sealingly engage and fluidly couple the exhaust device 200 and the dressing 100. As shown in FIG. 11B, in still other embodiments, the exhaust device 200 is optionally integrated within a module 300, and the module 300 is fixedly or removably attached to the dressing 100 so as to define an integrated, self - contained, one - piece treatment system 10.

[0044] In addition to the use of the treatment system 10 as a stand-alone decompression therapy device, in various embodiments, the treatment system 10 can be used with one or more additional treatment systems (and, optionally, can be integrated within one or more additional treatment systems). For example, although the treatment system 10 is described as being used to apply a tensile force onto intact skin surrounding the treatment tissue site, in some embodiments, the treatment system 10 can be used to apply a tensile force onto a wound. In some such embodiments, the treatment system 10 is optionally applied on top of (or integrated within) the wound dressing of a negative pressure wound therapy ("NPWT") system. In still other embodiments, the treatment system 10 can be used with various other treatment systems, such as, for example, a heat treatment system, a system configured to treat a fracture, and the like.

[0045] Dressing Referring to FIG. 3, the dressing 100 generally includes a flexible occlusion layer 110 and a compressible decompression layer 120 (e.g., a manifolding layer, a macromesh layer, a compressible layer, a crushable layer, etc.) that includes a plurality of fluid flow paths extending therethrough. The occlusion layer 110 is configured to be attached to the patient (e.g., using optional sealing members) so as to define a treatment chamber surrounding the treatment tissue site. Upon attachment of the dressing 100 to the patient, the decompression layer 120 is disposed within the treatment chamber and extends along the treatment tissue site. An optional interface layer 130 extends between the patient's skin and the decompression layer 120.

[0046] During operation of the treatment system 10, the expulsion of air from the treatment chamber at the start of the evacuation device 200 causes the occlusion layer 110 and the decompression layer 120 to be drawn towards the intact skin surrounding the treatment tissue site. When the vacuum applied by the evacuation device 200 removes most of the air from the treatment chamber, the continued application of negative pressure to the treatment chamber causes the compressible decompression layer 120 to be crushed (e.g., compressed) onto itself. This continued application of negative pressure to the treatment chamber and the crushing of the decompression layer 120 pulls the intact skin at the treatment tissue site outwardly (e.g., as indicated by the arrows in FIG. 2), thereby stimulating blood perfusion and lymphatic flow in the subcutaneous portion of the treatment tissue site.

[0047] A. Occlusion layer The occlusion layer 110 is configured to be sealed to the patient's skin so as to surround (e.g., enclose, extend over, cover, etc.) the treatment tissue site. For example, in some embodiments where the occlusion layer 110 is defined by a sleeve-like structure, a boot-like structure, or other annular structure and / or a sheet-like or tape-like structure configured to be wrapped around an anatomical structure, the occlusion layer 110 extends (i.e., surrounds) approximately 360 degrees around the patient's limb, extremity, or other anatomical structure, or extends more than 360 degrees (i.e., the occlusion layer 110 wraps around itself). In other embodiments (e.g., during treatment of the knee, shoulder, elbow, etc.), the occlusion layer 110 is optionally defined by a sheet-like structure that extends less than 360 degrees (e.g., less than 180 degrees) around the patient's anatomical structure.

[0048] Upon operation of the evacuation device 200, the sealed attachment between the occlusion layer 110 and the patient's skin forms a sealed decompression treatment chamber, through which negative pressure is transmitted to the treatment tissue site. The aperture 111 is optionally defined through the occlusion layer 110, through which the treatment chamber is fluidly coupled to the evacuation device 200 of the treatment system 10. Alternatively, the treatment chamber is fluidly coupled to a vacuum source via a connector interposed between the patient's skin and the lower surface of the occlusion layer 110.

[0049] The occlusion layer 110 can be formed from a variety of materials capable of maintaining a desired vacuum within the treatment chamber during use of the treatment system 10. The occlusion layer 110 is optionally formed from a material having a high MVTR to allow moisture (e.g., sweat) to evaporate from the treatment tissue site during use of the treatment system 10. The material selected for the occlusion layer 110 is also advantageously strong and elastic enough to allow the occlusion layer 110 to withstand long-term use of the treatment system 10. In embodiments where the occlusion layer 110 is reusable, the material forming the occlusion layer 110 also optionally has sufficient durability to allow the occlusion layer 110 to be cleaned (e.g., washed) between uses.

[0050] As shown in FIG. 3, in some embodiments, the occlusion layer 110 is provided as a separate, distinct component of the dressing 100 that is integrated with other components (e.g., the reduced pressure layer 120, the interface layer 130, etc.) during attachment of the dressing 100 to the patient. In some such embodiments, the occlusion layer 110 optionally has an adhesive provided along the lower surface of the occlusion layer 110. Such a peel-and-place arrangement (where the occlusion layer 110 is integrated with the sealing member) allows the dressing 100 to be quickly wrapped (or otherwise attached) around the patient's anatomical structure (e.g., foot, leg, arm, etc.), enabling rapid attachment of the dressing 100 to the patient. Referring to the exemplary embodiments of FIGS. 8A, 9A, and 10, in other embodiments, the occlusion layer 110 is alternatively removably or fixedly integrated with the reduced pressure layer 120.

[0051] Non-limiting examples of materials that can be used for the occlusion layer 110 include polyurethane films (e.g., ESTANE 5714F), other polymer films including, but not limited to, polyalkoxyalkyl acrylates and methacrylates (e.g., the polymer film described in UK Patent Application Publication No. 1280631(A) filed on Nov. 22, 2002, the entire disclosure of which is incorporated herein by reference), laminated fabrics (e.g., polyurethane laminated fabrics, expanded polytetrafluoroethylene laminated fabrics, etc.), polymer-coated fabrics, fabrics made from various synthetic fibers, and the like.

[0052] B. Reducing pressure layer The reducing pressure layer 120 (e.g., a manifold layer, a macro mesh layer, a compressible layer, a crushable layer, etc.) is configured to apply a tensile force or a lifting force onto the skin at the treatment tissue site. The reducing pressure layer 120 is formed from a material that includes (or defines) a plurality of fluid flow paths (e.g., paths, passages, pores, etc.) therethrough. The fluid flow paths of the reducing pressure layer 120 enable the continuous transmission of negative pressure to the treatment tissue site (e.g., manifolding) during the operation of the treatment system 10. Some or all of the fluid flow paths are optionally interconnected to improve the distribution of fluid (e.g., air) provided to or removed from the treatment tissue site. The reducing pressure layer 120 is formed from a compressible material having sufficient rigidity to provide an air flow through the fluid flow paths at a negative pressure of at least about 150 mmHg.

[0053] Referring to FIG. 2, when air is discharged from the treatment chamber during operation of the treatment system 10, the rigidity of the skin / muscle / bone under the treatment tissue site, which is greater than the rigidity of the dressing 100, causes the occlusion layer 110 to be attracted to the surface 125 facing outward of the decompression layer 120 (e.g., the upper surface, the outer surface, the surface facing away from the tissue site, etc.), and also causes the surface 127 of the decompression layer 120 facing the tissue (e.g., the lower surface, the inner surface, etc.) to be attracted toward and against the skin at the treatment tissue site (either directly or indirectly via an optional interface layer 130). When air is substantially discharged from the treatment chamber, the continued application of vacuum to the treatment chamber results in the collapse of the compressible decompression layer 120.

[0054] The direction in which the decompression layer 120 collapses (e.g., compresses) (i.e., outward / inward, upward / downward, away from the tissue site / toward the tissue site, radially, vertically, etc.) varies depending on the construction of the decompression layer 120. The collapse of a decompression layer 120 formed from a material having a single layer and a uniform density in response to vacuum is typically shown in FIG. 4A. As shown by the arrows in FIG. 4A, such a decompression layer 120 having a rigidity center located closer to the surface 127 facing the tissue than the surface 125 facing outward of the decompression layer 120 compresses such that the surface 125 facing outward of the decompression layer 120 is attracted toward the surface 127 of the decompression layer 120 facing the tissue.

[0055] An outer portion formed from a rigid material (i.e., the portion of the reduced-pressure layer 120 adjacent to the outward-facing surface 125 that faces away from the tissue site) and an inner portion formed from a softer material (i.e., the portion of the reduced-pressure layer 120 adjacent to the surface 127 that faces the tissue) of the reduced-pressure layer 120 collapsing in response to a vacuum is shown in FIG. 4B. In contrast to the exemplary reduced-pressure layer 120 shown in FIG. 4A, the reduced-pressure layer 120 as shown in FIG. 4B, defined by a rigidity center located near the outward-facing surface 125 of the reduced-pressure layer 120 rather than the surface 127 that faces the tissue, experiences a parallel plate effect when subjected to a vacuum during use of the treatment system 10. As shown by the arrows in FIG. 4B, this arrangement where the softer inner half of the reduced-pressure layer 120 is sandwiched between two harder structures (i.e., the skin / muscle / bone beneath the treatment tissue site and the relatively harder outer half of the reduced-pressure layer 120) results in the surface 127 that faces the tissue of the reduced-pressure layer 120 being drawn towards the outward-facing surface 125 of the reduced-pressure layer 120 when the reduced-pressure layer 120 collapses. The tensile force applied to the skin at the treatment tissue site as a result of such an outward-directed collapse of the reduced-pressure layer 120 is effective in improving lymph flow and blood perfusion at the treatment tissue site.

[0056] In view of the influence of the parallel plate effect on lymph flow and blood perfusion at the tissue site, the reduced-pressure layer 120 is advantageously constructed such that the rigidity center of the reduced-pressure layer 120 is located nearer to the outward-facing surface 125 of the reduced-pressure layer 120 than the surface 127 that faces the tissue. The reduced-pressure layer 120 is also advantageously constructed from a material having sufficient flexibility to allow the reduced-pressure layer 120 to be secured to the patient and to allow for the range of motion of the body part to which the dressing 100 is attached during use of the treatment system 10.

[0057] The decompression layer 120 is also preferably formed with sufficient structural integrity and elasticity to withstand repeated application of negative pressure to the decompression layer 120 over the course of operation of the treatment system 10 (e.g., for a period of up to one week or more than one week). To facilitate reuse of the treatment system 10 on the same patient or other patients, the decompression layer 120 is additionally optionally constructed with durability that allows the decompression layer 120 to be cleaned between uses.

[0058] Referring to FIG. 5, the construction of a decompression layer 120 having flexibility, elasticity, and durability configured to apply increased tensile forces onto the skin at the tissue treatment site is shown by way of an exemplary embodiment. In the embodiment of the decompression layer 120 of FIG. 5, the decompression layer 120 is defined by a macro-mesh material including a lower layer 123, an upper layer 121, and an intermediate layer 122. When integrating the decompression layer 120 into the tissue treatment system 10, the lower surface of the lower layer 123 defines a surface 127 (e.g., lower surface, inner surface, radially inwardly extending surface, etc.) of the decompression layer 120 that faces the tissue, and the upper surface of the upper layer 121 defines a surface 125 (e.g., upper surface, outer surface, radially outwardly extending surface, etc.) of the decompression layer 120 that faces outward. The upper layer 121 and the lower layer 123 are offset perpendicular to each other and are interconnected to each other via an intermediate layer 122 (e.g., a connector layer).

[0059] The upper layer 121 and the lower layer 123 that define the macro-mesh material forming the decompression layer 120 can be defined by a variety of different materials. To provide the desired degree of elasticity and durability to the decompression layer 120, one or both of the upper layer 121 and the lower layer 123 are formed from a fabric material. The fabric can be defined by a variety of different weave patterns or non-woven patterns, weights, densities, fibers, stiffnesses, etc., depending on the desired properties of the decompression layer 120. According to various embodiments, one or both of the upper layer 121 and the lower layer 123 are formed from a polymer or nylon material (e.g., a polymer or nylon mesh).

[0060] To provide a desired offset center of rigidity (i.e., a center of rigidity located near the surface 125 facing outward of the decompression layer 120) to the decompression layer 120, the upper layer 121 is formed of a material different from that of the lower layer 123, has a different construction from the lower layer 123, or is otherwise different from the lower layer 123. For example, the upper layer 121 is formed of a material having a greater rigidity than the material used for the lower layer 123. The materials selected for the upper layer 121 and / or the lower layer 123 may optionally include coatings (e.g., antibacterial coatings, hydrophobic coatings, etc.) to provide additional desired features to the decompression layer 120.

[0061] The intermediate layer 122 can be formed from a variety of different materials. As shown in FIG. 5, according to various embodiments, the intermediate layer 122 has durability, elasticity, and flexibility (e.g., crushability, deflectability, bendability, compressibility, etc.) that enable the decompression layer 120 to be crushed (e.g., compressed, or otherwise reduce the distance between the upper layer 121 and the lower layer 123) one or more times during use of the treatment system 10. It is formed of a plurality of filament fibers 129. The filament fibers 129 forming the intermediate layer 122 can be defined by various yarn types (e.g., monofilament, multifilament, spun, etc.), diameter, length, material, weight, denier, density, rigidity, etc. The selection and arrangement of the filament fibers 129 can vary based on the desired characteristics of the manifold layer. For example, the length and density of the filament fibers 129 forming the intermediate layer 122 can vary based on the desired rigidity of the decompression layer 120.

[0062] The effect of varying the various characteristics of the arrangement of the two-layer decompression layer 120 of FIG. 5 on the tensile strength applied to the skin during operation of the treatment system 10 will be described with reference to FIGS. 6A - 6F and FIG. 7. The non-limiting characteristics of the embodiments of the decompression layer 120 shown in FIGS. 6A - 6E are provided in the table of FIG. 7.

[0063] Generally, for example, a decompression layer 120 including a macro mesh configuration, as typically represented by the embodiment of FIG. 5, is defined by a greater rigidity than a decompression layer 120 formed from a single-layer, uniform-density reticulated foam material. Thus, as shown in the table of FIG. 7, even if a two-layer decompression layer 120 is defined by a rigidity center located at (or substantially at) the center of the decompression layer 120 (as shown by the embodiments of FIGS. 6A and 6B, for example), the structure of the two-layer decompression layer 120 provides an improvement in blood perfusion and lymph flow at the treatment tissue site as compared to a decompression layer formed from a single-layer, uniform-density reticulated foam material.

[0064] For example, as shown in the table of FIG. 7, in one embodiment, an embodiment of a decompression layer 120 as shown in FIG. 6A, including a macro mesh configuration having an upper layer 121 and a lower layer 123 of high density and / or high rigidity (e.g., formed from a polyester material having a denier of about 3.4), can increase the perfusion degree and flow degree at the treatment tissue site by about 10.5% as compared to a decompression layer formed from a single-layer, uniform-density reticulated foam material. Also, as shown in the table of FIG. 7, in one embodiment, an embodiment of a decompression layer 120 as shown in FIG. 6B, including a macro mesh configuration having an upper layer 121 and a lower layer 123 of low density and / or low rigidity (e.g., formed from a polyester material having a denier of about 1.5), can increase the perfusion degree and flow degree at the treatment tissue site by about 7.7% as compared to a decompression layer formed from a single-layer, uniform-density reticulated foam material.

[0065] As shown by a comparison of the performance of the examples of the decompression layer 120 of FIGS. 6A and 6B, summarized in the table of FIG. 7, for example, increasing the density (and rigidity) of the material used to form substantially similar upper layer 121 and lower layer 123 of the decompression layer 120 as shown by the embodiment of FIG. 6A provides an increased tensile force as compared to an embodiment of a two-layer decompression layer 120 having upper layer 121 and lower layer 123 each formed from a material of lower density (and lower rigidity) (as typically represented by the embodiment of FIG. 6B).

[0066] As shown in the table of FIG. 7, the decompression layer 120 includes an upper layer 121 formed from a material of higher density (and higher stiffness) and a lower layer 123 formed from a material of lower density (and lower stiffness), and thus, the arrangement of the two-layer decompression layer 120, as typically shown in FIG. 6C, defined by a stiffness center located near the surface 125 facing outward of the decompression layer 120, imparts an increased tensile force onto the treatment tissue site as compared to, for example, the decompression layer 120 formed with both an upper layer 121 and a lower layer 123 formed from a material having the same density (and the same stiffness), such as the embodiments of the decompression layer in FIGS. 6A and 6B. For example, the embodiment of the decompression layer 120 in FIG. 6C (formed from a high-density / high-stiffness upper layer 121 and a lower layer 123) exhibits a 24.6% improvement in perfusion and flow as compared to a decompression layer formed from a single-layer, uniformly dense reticulated foam material, as compared to an improvement of 10.5% over the foam of the embodiment of the decompression layer 120 in FIG. 6A (formed from a high-density / high-stiffness upper layer 121 and a lower layer 123), and an improvement of 7.7% over the foam of the embodiment of the decompression layer 120 in FIG. 6B (formed from a low-density / low-stiffness upper layer 121 and a lower layer 123).

[0067] As shown in FIG. 7, similar to the materials used for the lower layer 123 and the upper layer 121 of the embodiment of the decompression layer 120 in FIG. 6C, the embodiment of the decompression layer 120 in FIG. 6D is formed from a high-density (and high-stiffness) material, and the lower layer 123 of the decompression layer 120 is also formed from a low-density (and lower stiffness) material. However, the embodiment of the decompression layer 120 in FIG. 6C includes a continuously extending upper layer 121, while the upper layer 121 of the embodiment of the decompression layer 120 in FIG. 6D is instead defined by strips of high-density (and high-stiffness) material, and the strips are separated from each other by portions of an intermediate layer 122 along which the upper layer 121 does not extend.

[0068] As a result of the configuration of the interrupted upper layer 121 of the embodiment of the decompression layer 120 of FIG. 6D, the center of rigidity of the decompression layer 120 of FIG. 6D is located closer to the surface 127 facing the tissue than to the surface 125 facing outward of the decompression layer 120. As shown in FIG. 7, the effect of the center of rigidity of the decompression layer 120 of FIG. 6D located near the surface 127 facing the tissue of the decompression layer 120 is that the embodiment of the decompression layer 120 of FIG. 6D applies less tensile force on the skin at the treatment tissue site than a single-layer reticulated foam-based decompression layer of uniform density. Thus, as shown in the table of FIG. 7, an arrangement of a decompression layer such as the arrangement of FIG. 6D can result in a 16.1% reduction in perfusion and flow at the treatment tissue site compared to a decompression layer formed from a single-layer reticulated foam material of uniform density.

[0069] The tensile strength applied on the skin by the decompression layer 120 can be further enhanced by constructing the decompression layer 120 such that the distance of the center of rigidity from the surface 127 facing the tissue of the decompression layer 120 is maximized. As described with reference to FIG. 6C, one such option for maximizing this distance is to increase the rigidity of the upper layer 121 of the decompression layer 120 relative to the rigidity of the lower layer 123 of the decompression layer 120. As shown in FIG. 7 and as shown by the embodiments of FIGS. 6E and 6F, an additional option for increasing the tensile force applied on the skin during use of the treatment system 10 is to increase the thickness of the decompression layer 120 (i.e., the distance between the surface 125 facing outward and the surface 127 facing the tissue).

[0070] As typically shown by the embodiments of FIGS. 6E and 6F, an increase in the thickness of the decompression layer 120 can be achieved by incorporating one or more additional fabric layers 128 (similar to the upper layer 121 or the lower layer 123) into the structure of the decompression layer 120. As shown in FIGS. 6E and 6F, these one or more additional layers 128 can be integrated into the structure of the decompression layer 120 via one or more additional intermediate layers 122. To maximize the tensile force applied on the skin by the decompression layer 120, the additional fabric layer 128 is preferably integrated into the decompression layer 120 in a manner that maintains the rigid center of the decompression layer 120 near the surface 125 facing outward. For example, as shown by the embodiment of FIG. 6E, the decompression layer 120 can include the decompression layer 120 of FIG. 6A that is bonded or otherwise attached along the surface 125 facing outward of the decompression layer 120 of FIG. 6B. As shown in Table 7, such a multi-layer configuration of the decompression layer 120 as shown by the embodiment of FIG. 6E can provide an increase in perfusion and flow at the treatment tissue site of 51.2% compared to a decompression layer formed from a single-layer, uniform-density reticulated foam material.

[0071] C. Interface Layer An optional interface layer 130 (i.e., the skin contact layer) is disposed adjacent to the patient's skin upon attachment of the dressing 100 to the patient. The interface layer 130 may be incorporated into the dressing 100 for various reasons and may be defined by various different characteristics. For example, the interface layer 130 can be configured to reduce discomfort and irritation during use of the treatment system 10, provide cooling, suck up liquid from the skin, function as an antibacterial barrier, create friction between the decompression layer 120 and the skin, and improve the lifting force applied on the skin by the decompression layer 120.

[0072] The material forming the interface layer 130 can be selected based on the desired characteristics of the interface layer 130. Generally, the optional interface layer 130 is constructed from a lightweight, thin material that does not impede the flow between the skin and the decompression layer 120 and does not irritate the skin. As shown in FIG. 11A, in some embodiments, the interface layer 130 can include a fabric such as a non-woven breathable fabric or other porous material. As shown in FIG. 3, in other embodiments, the interface layer 130 can be formed from a closed-cell material that includes a plurality of perforations or holes formed therethrough. The interface layer 130 is also optionally formed with sufficient durability and elasticity to allow for reuse of the interface layer 130.

[0073] The interface layer 130 can be integrated within the dressing 100 in various arrangements. In some embodiments, the interface layer 130 is provided separately and removably from the decompression layer 120, entirely. In some such embodiments, the interface layer 130 can be provided as a sock or sleeve that is slid over and around the treatment tissue site (e.g., a patient's leg or arm). Once in the desired position, the components of the decompression layer 120 and the occlusive layer 110 of the dressing 100 are attached to the patient. Such a separated arrangement advantageously allows the user to confirm that the interface layer 130 is smoothly placed taut along the skin prior to attachment of the remaining components of the dressing 100, thus minimizing the risk of pinching resulting from wrinkles along the interface layer 130 during use of the treatment system 10.

[0074] Alternatively, as shown, for example, by the embodiment of FIG. 8A, the interface layer 130 is attached partially or entirely along the surface 127 facing the texture of the reduced pressure layer 120. In some embodiments, the interface layer 130 is removably attached to the reduced pressure layer 120, allowing the interface layer 130 to be removed as desired (e.g., to clean the interface layer 130 prior to reuse of the treatment system 10). In other embodiments, the interface layer 130 is instead fixedly secured (e.g., by thermal adhesion, via an adhesive, via ultrasonic welding, etc.) to all or a portion (e.g., the periphery) of the lower surface of the reduced pressure layer 120. Such a fixed attachment of the interface layer 130 and the reduced pressure layer 120 can advantageously minimize the presence of loose spots between the interface layer 130 and the reduced pressure layer 120, which can reduce the generation of bulges and bubbles, thereby minimizing the risk of pinching during operation of the treatment system 10.

[0075] D. Sealing Member The sealing member of the dressing 100 is used to provide a sealed (e.g., liquid-tight) attachment between the occlusive layer 110 and the underlying surface (e.g., skin, a section of the occlusive layer 110 wrapped around the patient, an optional interface layer 130, etc.), enabling a vacuum to be generated and maintained within the treatment chamber surrounding the tissue treatment site. Advantageously, the sealing member is structured to be robust enough to maintain the desired negative pressure continuously or intermittently within the treatment chamber over the period of use of the treatment system 10. The sealing member is advantageously self-adhesive and can provide a liquid-tight attachment to various different surfaces, including, for example, skin, an optional interface layer 130, the reduced pressure layer 120, the occlusive layer 110, etc. In embodiments where the sealing member is reusable, the sealing member is advantageously sterilizable. Alternatively, the sealing member may be replaceable (e.g., removable) such that a new sealing member can be used for each subsequent use of the treatment system 10.

[0076] The sealing member can be defined by various sealing structures or combinations of various sealing structures. As shown in FIG. 9B, the sealing member can optionally include one or more individual components provided separately from other components of the dressing 100. For example, the sealing member can include a tape-like or film-like structure 141 (e.g., a thermoplastic elastomer gel strip, a silicone / acrylic trilaminate film, etc.) applied along the entire upper layer or outer periphery of the occlusion layer 110 to secure the dressing 100 to the patient. In other embodiments, the sealing member can alternatively or additionally include a wiper seal 143 (e.g., see FIG. 1), an adhesive (e.g., an acrylic or silicone adhesive), or other sealing structure (e.g., a gasket) provided along (e.g., integrally with) or disposed between the entire lower surface or periphery of the occlusion layer 110.

[0077] In various embodiments, the sealing attachment provided by the sealing member can be reinforced and / or hidden by a hook and loop fastener, an adhesive bandage, a cast protector, or other structure located on top of the dressing 100 after the dressing 100 is attached to the patient.

[0078] Dressing Configuration The size, shape, and configuration of the dressing 100 can vary depending on various factors including, for example, the treatment tissue site being treated, the patient being treated, the duration of the treatment being provided, etc. Additional features of the dressing 100 that can vary depending on the desired use of the treatment system 10 include, for example, the degree of adjustment of the dressing 100 to a particular treatment site, the degree to which the dressing 100 is attached to the patient, the incorporation of features that facilitate attachment of the dressing 100 to the patient, the degree of integration of the components of the dressing 100, etc.

[0079] As shown in FIGS. 9A and 10, according to various embodiments, the dressing 100 defines a closed annular structure configured to extend circumferentially at least 360 degrees around an entire limb or other extremity. When attached, the dressing 100 partially or entirely surrounds the extremity.

[0080] In some embodiments, the annular dressing 100 is defined by a generally tubular, sleeve-like structure that extends between a first open end and a second open end. In other embodiments, the sleeve-like annular dressing 100 extends between a first open end and a second open end and has a shape, size, and outer profile for attachment around a particular extremity of a patient. For example, referring to FIGS. 9A and 10, in some embodiments, the dressing 100 defines an open-toe boot structure configured to receive a foot. In other embodiments, the annular dressing 100 defines a receiving portion configured to receive a portion (or entirety) of a user's extremity (e.g., hand, foot, stump, etc.). The receiving portion is accessible via a single open end defined by the annular dressing 100. The receiving portion defined by the annular dressing 100 may generally have a cylindrical shape or, optionally, may define a structure having a shape, size, and outer profile for receiving a particular extremity of a patient. For example, the dressing 100 may include a glove or mitten structure for receiving a patient's hand or a sock or closed-toe boot structure for receiving a patient's foot. Such customization of the dressing 100 to a particular treatment tissue site may advantageously facilitate an airtight attachment of the dressing 100 to the treatment tissue site. The annularly extending dressing 100 optionally includes folds and / or other joint features configured to allow at least a partial degree of flexion or mobility during treatment using a therapy system.

[0081] The dressing 100 is defined by an annularly extending structure having one open end or two open ends, and in embodiments where the annularly extending structure is configured to surround or otherwise enclose a portion of a patient, the dressing 100 can be formed from a material that allows the dressing 100 to stretch during application of the dressing 100 around the patient. Alternatively or additionally, the dressing 100 optionally includes one or more features configured to facilitate application of the dressing 100 around the patient. For example, as shown in FIG. 10, the dressing 100 optionally includes a slit that extends partially or entirely along the length of the slit. Fitting engagement elements 151 (e.g., fitting zipper teeth, hook and pile, etc.) are optionally provided along the respective lengths of the edges defining the slit to allow the edges to selectively join and separate from each other. In some such embodiments, one or both of the edges optionally include a plurality of similar or identical engagement elements that are generally parallel and spaced apart from each other at one or more locations spaced inwardly from the edge, thus allowing the diameter of the dressing 100 to be adjusted as needed.

[0082] As an alternative to (or in addition to) constructing the dressing 100 from a material that provides slit elongation and / or inclusion of slits as typically shown in FIGS. 9A and 9B, the dressing 100 includes, in some embodiments, a gusset 153 that can be released (or incorporated) via tightening of an annularly extending strap 155 (e.g., a fitting hook and pile strap, etc.) to increase (or decrease) the size of the opening of the dressing 100. In still other embodiments, the components of the annular dressing 100 optionally additionally (or alternatively) are formed from an elastic material that allows the dressing 100 to stretch and expand to facilitate insertion of a limb or other appendage into the opening of the dressing 100 during attachment of the dressing 100 to the patient.

[0083] According to other embodiments, the dressing 100 can alternatively be defined by a flexible sheet-like structure. The sheet-like dressing 100 can be provided in a range of shapes and sizes. As typically shown by the embodiment of FIG. 3, in some embodiments, the sheet-like dressing 100 optionally has a shape and size for application to a particular treatment site.

[0084] As shown in FIGS. 8A and 8B, in some embodiments, the sheet-like dressing 100 can be wrapped around a treatment tissue site to substantially (e.g., entirely) surround a portion of the patient (e.g., calf, wrist, ankle, etc.). For example, the sheet-like dressing 100 can be configured to wrap around the patient's limb or limbs by more than about 360 degrees. Alternatively, as shown in FIGS. 11A and 11B, in other embodiments, the sheet-like structure defining the dressing 100 is attached to the patient as a patch, in which the outer perimeter of the sheet-like dressing 100 surrounds the treatment tissue site but does not surround the limb or limbs of the patient where the treatment tissue site is located (e.g., when the dressing 100 is applied over the knee or shoulder, for example, the dressing 100 can extend less than 360 degrees around the limb or limbs). In some such embodiments (and / or in other embodiments of the dressing 100), the dressing 100 optionally includes a thin semi-rigid flexible (e.g., bendable, conformable, etc.) reinforcement layer that enables the sheet-like dressing 100 to conform to the outer shape of the treatment tissue site to which the dressing 100 is attached, thereby facilitating attachment of the dressing 100 to the patient. As shown in FIGS. 11A and 11B, the sheet-like dressing 100 optionally includes folds and / or other articulation features 103 configured to allow at least partial flexion or mobility during treatment using the therapy system.

[0085] According to yet other embodiments, the dressing 100 may be provided as a flexible tape that can be wrapped around the treatment tissue site or attached over the apex of the treatment tissue site as one or more strips. Such an arrangement of the tape-like dressing 100 may provide the user with the ability to customize the attachment of the treatment system 10 for various different treatment sites and various different patients. In some embodiments, an adhesive is optionally provided along the outer periphery of the tape-like structure to facilitate attachment of the dressing 100 to the patient. In such embodiments, application of the tape-like structure such that adjacent sections of the tape (e.g., adjacent wraps or adjacent strips) overlap may enable the dressing 100 to be attached to the patient without the need for additional sealing of the dressing 100 to the patient. Alternatively, an additional sealing layer (e.g., the occlusion layer 110, etc.) may be attached to the patient so as to surround the tape-like dressing 100 applied to the patient.

[0086] The various configurations and features of the dressing 100 described above may apply to all or only some of the components of the dressing 100. For example, as typically illustrated by the embodiment of FIG. 1, in some embodiments, the occlusion layer 110 and the interface layer 130 may be defined by an annular structure configured to be slid over the patient's foot, and the decompression layer 120 may include a tape-like structure that can be wrapped around the occlusion layer 110 prior to attachment of the occlusion layer 110.

[0087] Configuration of Exemplary Embodiments As used herein, the terms "about," "approximately," "substantially," and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It will be understood by those of ordinary skill in the art who review this disclosure that these terms are intended to allow the description and claiming of certain features without limiting the scope of these features to the exact numerical ranges provided. Accordingly, these terms should be interpreted as indicating that non-substantive or insignificant modifications or variations of the described and claimed subject matter are considered to be within the scope of this disclosure as set forth in the appended claims.

[0088] As used herein to describe various embodiments, the terms "exemplary" and variations of the term "exemplary" are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (it should be noted that such terms are not intended to imply that such embodiments are necessarily special or the best examples).

[0089] As used herein, the terms "coupled" and variations of the term "coupled" mean connecting two members directly or indirectly to each other. Such connection may be stationary (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such connection may be achieved by the two members being directly coupled to each other, the two members being coupled to each other using separate intervening members and any additional intermediate members coupled to each other, or the two members being coupled to each other using an intervening member integrally formed as a single unitary body with one of the two members. When a variation of "coupled" or "coupled" is modified by an additional term (e.g., directly coupled), the general definition of "coupled" provided above is modified by the ordinary meaning of the additional term (e.g., "directly coupled" means the connection of two members without separate intervening members), resulting in a definition that is narrower than the general definition of "coupled" provided above. Such connection may be mechanical, electrical, or fluidic.

[0090] As used herein, the term "or" is used in its inclusive sense (and not in its exclusive sense), and thus when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Unless specifically stated otherwise, conjunctions such as the phrase "at least one of X, Y, and Z" are understood to convey that the element is any one of X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Thus, unless otherwise indicated, such conjunctions are not generally intended to mean that an embodiment requires the presence of at least one of each of X, at least one of Y, and at least one of Z.

[0091] References to the positions of elements in this specification (e.g., "top", "bottom", "above", "below") are used merely to describe the orientations of the various elements in the figures. It should be noted that the orientations of the various elements may differ according to other exemplary embodiments, and such variations are intended to be encompassed by this disclosure.

Claims

1. 1. An apparatus for applying a lifting force to a tissue site on a patient, comprising: an occlusion layer configured to be sealed to the patient about the tissue site to define a chamber; a reduced pressure layer disposed within the chamber defined by the occlusion layer and adjacent the tissue site, the reduced pressure layer including a compressible fabric defining one or more flow channels therethrough; a connector disposed along the closure layer and configured to fluidly couple the chamber to a vacuum source; In an apparatus comprising: the reduction pressure layer has a greater stiffness adjacent an upper surface of the reduction pressure layer away from the tissue site than a lower surface of the reduction pressure layer facing the tissue site such that upon operation of the vacuum source, the reduction pressure layer is configured to compress in a direction away from the tissue site; the reduction pressure layer further comprises a macromesh material including an upper layer proximate the upper surface of the reduction pressure layer, a lower layer proximate the lower surface of the reduction pressure layer, and a plurality of filaments extending between and connecting the upper layer and the lower layer, the upper layer having a higher stiffness than the lower layer.

2. 2. The device of claim 1, wherein the occlusion layer extends at least 360 degrees around a limb defining the tissue site when sealed to the patient, and the reduced pressure layer is configured to compress in a radially outward direction during operation of the vacuum source.

3. 2. The apparatus of claim 1, wherein the filament is flexible such that a distance between the upper layer and the lower layer before operation of the vacuum source is greater than a distance between the upper layer and the lower layer during operation of the vacuum source.

4. 2. The device of claim 1, wherein the macromesh material further comprises a first middle layer disposed between the upper layer and the lower layer in the plurality of filaments, the first middle layer having a higher stiffness than the lower layer.

5. The device of claim 4 , wherein the first middle layer comprises the same material as the top layer.

6. The device of claim 4 , wherein the plurality of filaments extend between the first middle layer and at least one of the lower layer and the upper layer.

7. 6. The device of claim 5, wherein the macromesh material further comprises a second intermediate layer disposed in the plurality of filaments between the top layer and the first intermediate layer, the second intermediate layer having a lower stiffness than the first intermediate layer.

8. 6. The device of claim 5, wherein the macromesh material further comprises a second intermediate layer disposed in the plurality of filaments between the bottom layer and the first intermediate layer, the second intermediate layer having a lower stiffness than the first intermediate layer.

9. The device of claim 8 , wherein the second middle layer comprises the same material as the bottom layer.

10. 10. The device of claim 1, further comprising an interface layer located beneath the lower surface of the reduced pressure layer, the interface layer contacting skin surrounding the tissue site upon sealing of the occlusive layer to the patient.

11. The device of claim 10 , wherein the interface layer is a separate and distinct structure from the reduced pressure layer and is selectively releasably attached to at least one of the reduced pressure layer and the occlusion layer.

12. The apparatus of claim 10 , wherein the interface layer is attached to the reduced pressure layer along a lower surface of the reduced pressure layer.

13. 2. The device of claim 1, wherein the occlusion layer and the reduction pressure layer are attached to one another to define an annular structure including at least a first open end, the annular structure being sized for attachment to one of the patient's knee, ankle, leg, arm, or hand.

14. The device of claim 13 , wherein the annular structure defines a sleeve-like structure further including a second open end.

15. 1. An apparatus for increasing at least one of blood perfusion and lymphatic flow at a tissue site, comprising: a circumferentially extending occlusive layer configured to be sealed to a patient about the tissue site to define a chamber; a reduced pressure layer having a lower surface configured to be disposed adjacent to the tissue site within the chamber defined by the occlusion layer; a connector configured to fluidly couple the chamber to a vacuum source; In an apparatus comprising: the reduction pressure layer has a greater stiffness adjacent an upper surface of the reduction pressure layer away from the tissue site than a lower surface of the reduction pressure layer facing the tissue site such that upon operation of the vacuum source, the reduction pressure layer is configured to compress in a direction away from the tissue site; The device, wherein the pressure reduction layer further includes a first mesh layer vertically offset from a second mesh layer by a flexible layer, the first mesh layer being located opposite the occlusion layer and the second mesh layer being located opposite the tissue site, the first mesh layer having a greater stiffness than the second mesh layer.

16. 16. The apparatus of claim 15, wherein the second mesh layer moves radially outward toward the first mesh layer during operation of the vacuum source.

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