WO2021161215A1

WO2021161215A1 - Wound dressing with dissolvable film

Info

Publication number: WO2021161215A1
Application number: PCT/IB2021/051134
Authority: WO
Inventors: Jonathan G. REHBEIN; Luke Perkins; Enrique L. SANDOVAL; Shervin JAHANIAN
Original assignee: Kci Licensing, Inc.
Priority date: 2020-02-13
Filing date: 2021-02-11
Publication date: 2021-08-19

Abstract

A wound dressing includes a patient interface layer having openings formed therethrough, an intermediate layer comprising at least one of an absorbent layer and a manifold layer disposed atop the patient interface layer, a drape layer disposed above the intermediate layer and comprising an adhesive material disposed at least partially on the drape layer, and an activation layer disposed on at least a portion of the adhesive material and comprising a dissolvable material.

Description

WOUND DRESSING WITH DISSOLVABLE FILM

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of priority to U.S. Provisional Application No. 62/976,057, filed on February 13, 2020, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] The present disclosure relates generally to wound dressings. More specifically, the present disclosure relates to wound dressings with an adhesive layer. In many instances, a wound dressing is applied to a surface of a patient using an adhesive material disposed on the wound dressing. Upon application, the adhesive material secures a location of the wound dressing relative the surface of the patient and may be difficult to reposition if needed. Additionally, prior to application, the dressing may fold and adhere to itself rendering the dressing difficult to use. It would be desirable to provide a dressing which permits placement and repositioning of the dressing before adhering to a surface on a patient.

SUMMARY

[0003] One implementation of the present disclosure is a negative pressure wound therapy system. The negative pressure wound therapy system includes a dressing configured to be sealed over a wound, a conduit coupled to the dressing, and a negative pressure therapy unit coupled to the conduit. The dressing includes a drape layer comprising an adhesive material disposed on the drape layer and an activation layer disposed on the drape layer and comprising a dissolvable material.

[0004] In some embodiments, the dissolvable material dissolves and exposes the adhesive material upon activation of the activation layer. The activation layer can further include a medicinal material. [0005] In some embodiments, the activation layer comprises at least one opening formed therethrough and configured to permit passage of the adhesive material to the area around the wound. The passage of the adhesive material through the at least one opening provides an initial bond configured to adhere the dressing in a desired position until the activation layer is activated. A thickness of the activation layer is variable to provide a variable activation period. The drape layer can further include an opening providing an interface with the conduit.

[0006] Another implementation of the present disclosure is a dressing. The dressing includes a patient interface layer having openings formed therethrough, an intermediate layer comprising at least one of an absorbent layer and a manifold layer disposed atop the patient interface layer, a drape layer disposed above the intermediate layer and comprising an adhesive material disposed at least partially on the drape layer, and an activation layer disposed on at least a portion of the adhesive material and comprising a dissolvable material. [0007] In some embodiments, the dissolvable material dissolves upon exposure to perspiration and exposes the adhesive material upon activation of the activation layer. The activation layer can further include a medicinal material.

[0008] In some embodiments, the activation layer includes at least one opening formed therethrough and configured to permit passage of the adhesive material to the area around the wound. The passage of the adhesive material through the at least one opening can provide an initial bond configured to at least partially adhere the dressing in a desired position until the activation layer is activated. A thickness of the activation layer is variable between a first reduced thickness to provide a reduced activation period and a second greater thickness to provide a greater activation period.

[0009] Yet another implementation of the present disclosure is a method of making a wound dressing. The method includes providing a drape layer, applying an adhesive material to at least a portion of the drape layer, and depositing a dissolvable material over at least a portion of the adhesive material.

[0010] The drape layer may be provided having at least one opening for coupling to a negative pressure therapy device. The method may involve providing an absorbent core comprising an absorbent material and placing the absorbent core beneath the drape layer. Providing the dissolvable material may involve providing the dissolvable material with a medicinal material.

[0011] Yet another implementation of the present disclosure is a method of applying a wound dressing. The method involves positioning the wound dressing on a patient, the wound dressing having an adhesive material at least partially covered with a dissolvable material, and activating the wound dressing by dissolving the dissolvable material to expose the adhesive material.

[0012] In some embodiments, the method further involves applying moisture to initiate activation of the dissolvable material.

BRIEF DESCRIPTION OF THE DRAWINGS [0013] Various objects, aspects, features, and advantages of the disclosure will become more apparent and better understood by referring to the detailed description taken in conjunction with the accompanying drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.

[0014] FIG. 1 is a cross-sectional assembled view of a dressing with an activation layer, according to an exemplary embodiment.

[0015] FIG. 2 is an exploded view of a dressing with an activation layer, according to an exemplary embodiment.

[0016] FIG. 3 is a schematic representation of a negative pressure and instillation wound therapy (NPWT) system, according to an exemplary embodiment.

[0017] FIG. 4 is a flowchart illustrating a method of making a dressing with an activation layer, according to an exemplary embodiment. [0018] FIG. 5 is a flowchart illustrating a method of applying a dressing with an activation layer, according to an exemplary embodiment.

[0019] FIG. 6 is a flowchart illustrating a method of applying negative pressure and instillation wound therapy using the NPWT system of FIG. 3, according to an exemplary embodiment.

DETAILED DESCRIPTION

Overview

[0020] Referring generally to the FIGURES, a wound dressing with an activation layer is shown, according to various exemplary embodiments. The dressing may include one or more layers such as a patient interface layer, an intermediate layer, a drape layer, and activation layer, each of which will be described in greater detail below. The patient interface layer may be a fenestrated fdm disposed on or over a wound area (e.g., a wound bed, a periwound, a region, etc.). The fenestrations provided by the patient interface layer are intended to permit passage of fluid (e.g., wound exudate) from the wound and through the patient interface layer. In some embodiments, the patient interface layer is coated with a low-tack adhesive such as silicone providing substantial position retention of the patient interface layer relative the wound.

[0021] The intermediate layer is disposed atop the patient interface layer and is fluidly and/or physically coupled with the patient interface layer. The intermediate layer may be structured as an absorbent core and formed of any suitable material (e.g., foam, superabsorbent polymer) configured to draw fluid (e.g., wound exudate) from the wound and through the patient interface layer. In various embodiments, the intermediate layer is coated with an antimicrobial agent such as silver, cadexomer iodine, polyhexamethyl biguanide, or honey. In some embodiments the patient interface layer is structured as a manifold layer and configured to generate a negative pressure manifolding effect across the wound bed. The manifolding effect allows airflow therethrough and facilitates the distribution of negative pressure across the wound bed when using negative pressure wound therapy. Accordingly, it should be understood that, in some embodiments, the intermediate layer may include both an absorbent core and a manifold layer. In such embodiments, the manifold layer may be disposed atop, beneath, or incorporated into the absorbent core.

[0022] The drape layer may be formed of any suitable high moisture vapor transmission rate (MVTR) material such as Inspire 2327/2317. In some embodiments, the drape layer is configured for placement atop the intermediate layer and the patient interface layer and provides substantial protection of the dressing (e.g., patient interface layer, intermediate layer) from an external environment. The drape layer may include one or more negative pressure communication holes configured to fluidly couple the dressing to a negative pressure therapy unit via conduit, tube, or lumen.

[0023] The drape layer includes an adhesive layer disposed on an underside of the drape layer (e.g., on a wound-facing side of the drape layer) and may include any suitable type of adhesive material, such as acrylic adhesive, to retain the position and seal of the dressing relative to the wound. The adhesive layer can be disposed on a wound-facing side of the drape layer such that the adhesive layer couples with a surface of the patient (e.g., wound, periwound, skin) upon application of the dressing to the wound. The adhesive layer may be applied to at least an area of the surface of the drape layer that is disposed around a wound bed.

[0024] The activation layer is intended to at least partially cover the adhesive layer and comprises a dissolvable material such as a hydrophilic polymer that dissolves when exposed to moisture. The activation layer is disposed beneath at least a portion of the adhesive material. Prior to the dissolution of the dissolvable material, the activation layer provides a barrier layer between the adhesive layer and an area around a wound (e.g., wound, periwound, skin, patient surface) intended to prevent or minimize adhesion of the adhesive layer to the area around the wound. Accordingly, upon dissolution of the dissolvable material (e.g., activation of the activation layer), the dissolvable material exposes the adhesive material to the patient surface allowing for the adhesive material to adhere to the patient surface and secure the dressing relative the patient surface. As will be described in greater detail, the activation layer may activated by applying moisture to the patient surface to which the adhesive layer is applied prior to application of the dressing. In various arrangements, the activation layer includes one or more openings formed therethrough and configured to permit passage or exposure of the adhesive material to the area around the wound. As such, the passage or exposure of the adhesive material through the one or more openings to the area the wound provides for an initial or preliminary adhesion of the adhesive material to the area around the wound.

[0025] The dressing may be used as part of a NPWT system. The NPWT system may include a therapy device having an instillation fluid canister, a removed fluid canister, one or more valves, a pneumatic pump, an instillation pump, atubeset module, and a controller. As previously described, the dressing can be applied to a patient’s skin surrounding a wound. The therapy device can be configured to deliver instillation fluid to the wound and provide NPWT by maintaining the wound at negative pressure. Components of the wound therapy device, the wound dressing, and the wound site form a negative pressure circuit.

[0026] The controller can be configured to operate the pneumatic pump, the instillation pump, the tubeset module, and/or other controllable components of the therapy device. In some embodiments, the controller estimates the volume of the wound based on a comparison of observed dynamic pressure responses to negative pressure being applied to the entirety of the negative pressure circuit and negative pressure being applied to a selected portion of the negative pressure circuit. Based on the comparison of the observed dynamic responses, the controller may be configured to determine a quantity of instillation fluid to be delivered to the wound site. The observed dynamic pressure responses can be measured using one or more sensors. The one or more sensors are configured to measure the pressure of fluid flowing past and engaging with the each sensor. Dressing with Activation Layer Having Dissolvable Film Feature

[0027] Referring now to FIGS. 1 & 2, a dressing 102 according to an exemplary embodiment. The dressing 102 is shown to include a drape layer 202 configured to be sealed around and over a wound, an adhesive material 204 disposed on the drape layer 202, an activation layer 206 disposed beneath at least a portion of the adhesive material 204, a patient interface layer 208 disposed beneath at least a portion of the drape layer 202, and an intermediate layer 210 disposed atop the patient interface layer 208.

[0028] The drape layer 202 is configured to protect both the wound bed and any external surfaces from contamination. The drape layer 202 may be a thin high moisture transmission rate (MVTR) polyurethane film such as Inspire 2327/2317. In some embodiments, the drape layer 202 includes at least one fluid communication hole 212 formed therethrough and configured to fluidly couple the dressing 102 with a therapy device (e.g., therapy unit 108). In such embodiments, the at least one fluid communication hole 212 is configured to receive a fluid conduit (e.g., first tubing 106, second tubing 112) and fluidly communicate, via the fluid conduit, with one or more therapy devices (e.g., therapy unit 108). Although the drape layer 202 is shown to include two fluid communication holes 212, it should be understood that drape layer 202 may include any number of fluid communication holes 212. In some embodiments, drape layer 202 includes on fluid communication hole 212. Fluid communication holes 212 may be located anywhere on the drape layer 202. For example, a fluid communication hole 212 may be located proximate an edge of drape layer 202, or may be centrally disposed on the drape above the intermediate layer.

[0029] The adhesive material 204 is disposed on the drape layer 202 and configured to engage an area around a wound bed to secure a location of the dressing 102 relative the wound bed. The adhesive material 204 may be any desirable adhesive material, such as an acrylic adhesive, Tegaderm, silicone, etc. As shown in FIG.23, the adhesive layer is disposed on at least a portion of the drape layer 202 surrounding a wound. In some embodiments, the adhesive material is disposed around an entirety of a wound bed. In some embodiments, the adhesive material 204 is pattern coated onto the drape layer 202. The adhesive material 204 may include at type of suitable adhesive configured to substantially retain the position of the dressing relative the wound. The adhesive material 204 may be disposed on a wound-facing surface of drape layer 202.

[0030] The activation layer 206 is disposed on (i.e., on the wound-facing side) at least a portion of the adhesive material 204 and configured to provide at least a partial barrier between the adhesive material 204 and a patient surface (e.g., area around a wound, periwound, wound). In other words, the activation layer 206 temporarily prevents or minimizes the adhesive material 204 from engaging and adhering the drape (and thus, the dressing 102) to the patient surface. Upon “activation” of the activation layer 206, the activation layer 206 dissolves, dissipates, or erodes and exposes the adhesive material 204 to the patient surface to allow the adhesive material to adhere (or more completely adhere) the dressing 102 to the patient surface. The activation layer 206 may be a dry film polymer coating that is activated via moisture presence or application at the dressing placement site (e.g., spraying the patient surface with a liquid such as water) and dissolving, dissipating, or eroding, via the applied moisture, the activation layer 206. Alternatively, the activation layer 206 may be activated by perspiration from a patient. For example, sweat produced by a patient may activate the activation layer 206. Accordingly, upon dissolution of the activation layer 206, the dissolved activation layer 206 may evaporate through the adhesive material 204 and drape layer 202 or may be withdrawn via a NPWT system. Activation layer 206 may also comprise any desirable medicinal material such as, but limited to, a pain reliever or an anti-inflammatory.

[0031] Activation layer 206 comprises a material that sufficiently covers the adhesive and is effective to prevent or minimize adherence of the underlying adhesive to a surface of a patient until proper positioning of the dressing is established. Once proper positioning (or repositioning) of the dressing is established, activation layer 206 may be 'activated’ (e.g. dissolved, evaporated, inactivated, etc.) to expose the adhesive properties of the adhesive layer to the surface of the patient for securing the dressing. According to one embodiment, activation layer 206 may comprises a material such as a polymer film that may contain reagents or other active materials designed to erode or dissolve at predetermined rates when in contact with a biological fluid or other liquid, such as are commercially available from Adhesives Research, Inc. Such polymer films in the form of an activation layer are an efficient medium for stabilizing sensitive reagents, delivering therapeutic agents or dispersing pigments. The dissolvable films’ dissolution rates may be customizable to deliver a specified release over time. The dissolvable films are also intended to provide other advantages for use with a wound dressing, including (among others): tailorable characteristics such as thickness, dissolution rate, texture and tensile strength; provide concentrated doses of reagent or therapy within a homogeneous film coating; enhanced stability of reagent or active ingredient in a dry film format, more efficient use of reagents and active ingredients compared to other distribution techniques; and allows separation of reagents and active ingredient within a dry, dissolvable film format. All of these characteristics are intended to be within the scope of this disclosure.

[0032] The activation layer 206 may include any suitable thickness to adjust an activation period to dissolve the activation layer 206. An activation period is defined herein as the amount of time for activation layer 206 to dissolve, exposing the adhesive material 204 to the patient surface, for the adhesive material 204 to adhere to the patient surface. It may be desirable to provide an activation layer 206 having a larger thickness (relative to a standard thickness) to provide a longer or greater activation period. As such, activation layer 206 may include a reduced thickness to provide a shorter or reduced activation period. The activation period of activation layer 206 may be “dialed-in” by providing activation layer 206 with a specifically desired thickness. The activation layer 206 may optionally include any number of openings 214. The openings 214 are configured (when present) to permit an initial passage of the adhesive material 204 to the patient surface to allow for initial adhesion of the dressing 102 to the patient surface to permit preliminary positioning of the dressing 102 in a repositionable manner prior to activation of the activation layer 206. The openings 214 may be disposed at any desirable location on the activation layer 206 and may include any desirable size, shape, or configuration.

[0033] The patient interface layer 208 is configured to overlie wound bed 114. The patient interface layer 208 includes an upper surface and lower, wound-facing surface. The upper surface may be fluidly and/or physically coupled with drape layer 202. In some embodiments in which dressing 102 includes intermediate layer 210, the upper surface of patient interface layer 208 is fluidly and/or physically coupled with, or disposed adjacent to, intermediate layer 210. The lower surface is configured to overlie the wound bed (e.g., wound bed 114). The patient interface layer 208 may be made from a polymer film (e.g., polyurethane film) or a medical textile (e.g., Asahi nylon). In some embodiments, the patient interface layer 208 extends laterally beyond an outer perimeter of intermediate layer 210. In other embodiments, the patient interface layer 208 may be substantially the same size and/or shape as the intermediate layer 210. The patient interface layer 208 may include a plurality of openings formed therethrough (e.g. in the form of fenestrations, etc.) and configured to permit passage (e.g., to the at least one fluid communication hole 212, to the intermediate layer 210) of a fluid from a wound when used in NPWT applications. The openings may be structured as substantially circular holes disposed in a regular pattern across the patient interface layer 208. The size, shape, number, and arrangement of holes may be different in various alternative embodiments. [0034] The intermediate layer 210 is disposed atop and is fluidly and/or physically coupled with the patient interface layer 208. The intermediate layer 210 may be structured as one or more of an absorbent core and/or a manifold layer. In embodiments in which the dressing is an advanced wound dressing without NPWT, intermediate layer 210 is structured as an absorbent core and is configured to absorb fluid (e.g., wound exudate) and drain the fluid from a wound bed. In such embodiments, the intermediate layer 210 includes a super absorbent polymer (SAP) material. In some embodiments, the intermediate layer 210 includes a plurality of nodules, dots, bumps, lumps, islands, protuberances, or other suitable form of deposition of a superabsorbent polymer material. In some embodiments, intermediate layer 210 may also be formed or otherwise include a superabsorbent polymer in the form of granules. The superabsorbent polymer may include Luquasorb 1160 or 1161, such as may be commercially available form BASF. The granules or deposits may be contained in a water-soluble carrier polymer. One example of the water-soluble carrier polymer is polyvinylpyrrolidone (PVP). The superabsorbent polymer and the water-soluble polymer may be formed into a slurry or a suspension using an organic solvent.

[0035] In some embodiments, the superabsorbent polymer is disposed in a layer of variable thickness across the intermediate layer 210. In some such embodiments, the superabsorbent polymer comprises a thicker layer proximate an outside edge of the intermediate layer 210 such that an inner, thinner layer of super absorbent polymer is formed proximate a center of the intermediate layer 210. In embodiments, where the dressing is used in NPWT applications, the intermediate layer 210 may be formed from a hydrophilic foam material to provide a manifold layer configured to generate a manifolding effect. Such a manifold layer may be used in a NPWT to allow flow therethrough and facilitates the distribution of negative pressure across a wound bed.

Wound Therapy System

[0036] Referring to FIG. 3, the dressing 102 can be used in an NPWT system 100, according to an exemplary embodiment. The NPWT system 100 includes dressing 102 fluidly communicable with a canister 104 via first tubing 106 and a therapy unit 108 coupled to the canister 104. As shown in FIG. 3, the NPWT system 100 also includes an instillation fluid source 110 fluidly communicable with the dressing 102 via the therapy unit 108 and second tubing 112.

[0037] First tubing 106 includes an inner lumen 116 extending between the canister 104 and the dressing 102 and one or more outer lumens 118 extending between therapy unit 108 and dressing 102. The inner lumen 116 provides for the flow of fluid from the wound space 120 into the canister 104. Inner lumen 116 may be fluidly communicable with a first sensor 123 to facilitate measurement of the pressure at wound space 120. The inner lumen 116 is also fluidly communicable with a first valve 125 as described below. The one or more outer lumens 118 are fluidly communicable with a second sensor 124. Second sensor may collect similar measurements as first sensor 123. In various embodiments, systems 100 includes both first sensor 123 and second sensor 124. The one or more outer lumens 118 are also fluidly communicable with a second valve 126 as described below. It should be understood that, while described as inner and outer in the examples herein, any geometrical arrangement of multiple lumens may be used in various embodiments.

[0038] The canister 104 is configured to collect wound exudate (e.g., fluid, other debris) removed from the wound space 120 via the first tubing 106. The canister 104 is fluidly communicable with the wound space 120 via the first tubing 106. The canister 104, the first tubing 106, and the dressing 102 thereby define a sealed space that includes the wound space 120. The canister 104 is shown to include a filter 138 configured to restrict flow of debris (e.g., wound exudate) from canister 104 into therapy unit 108. As shown, filter 138a is disposed in canister 104 and within a fluid path defined by outer lumen 118. Filter 138b is shown to be disposed in canister 104 and within a fluid path defined by inner lumen 116.

[0039] The therapy unit 108 is pneumatically coupled to the canister 104 and includes a pneumatic pump 122 fluidly communicable with the sealed space, a first sensor 123 configured and positioned to measure pressure in the sealed space, a first valve 125 positioned between the pneumatic pump 122 and the canister 104, a user interface 128, and an instillation pump 130 coupled to the second tubing 112. The therapy unit 108 also includes a control circuit 132 communicably and operably coupled (e.g., capable of exchanging electronic signals with) the pneumatic pump 122, the first sensor 123, the first valve 125, the second sensor 124, the second valve 126, the user interface 128, and the instillation pump 130. [0040] The pneumatic pump 122 is controllable by the control circuit 132 and operable to pump (e.g., draw, remove) air from the canister 104, the first tubing 106, and the wound space 120 (i.e., from the sealed space). The pneumatic pump 122 may thereby create a negative pressure in the sealed space relative to atmospheric pressure, for example between 25 mmHg and 175 mmHg. The pneumatic pump 122 may create a pressure differential that causes fluid and debris to be drawn out of the wound space 120, through the first tubing 106, and into the canister 104.

[0041] The first sensor 123 and the second sensor 124 are positioned and configured to measure the pressure in the sealed space. As shown in FIG. 3, the first sensor 123 is positioned to measure pressure within a fluid path defined by inner lumen 116 and therapy unit 108. As shown in FIG. 3, the second sensor 124 is positioned to measure pressure via one or more outer lumens 118. In other embodiments, second sensor 124 may be include to measure pressure elsewhere in the sealed space (e.g., in the canister 104). The first sensor 123 provides pressure measurements to the control circuit 132 (e.g., digital values, analog signals). The control circuit 132 may be configured to receive the pressure measurements from the first sensor 123 and use the pressure measurements in a control loop to generate control signals for the pneumatic pump 122 that cause the pneumatic pump 122 to maintain a desired pressure in the sealed space or provide a desired pattern of pressure in the sealed space.

[0042] The user interface 128 may include a display screen, a touch screen, a speaker, a button, a switch, or any other element capable of providing information to a user or receiving input from a user. In some embodiments, the control circuit 132 is configured to generate a graphical user interface and cause the graphical user interface to be displayed on the user interface 128. The graphical user interface may include various information about the NPWT provided by the NPWT system 100, for example relating to the pressure in the sealed space, an amount of instillation fluid to be provided, a schedule of negative pressure and instillation cycles, and/or a size of the wound space 120. The user interface 128 may allow a user to input commands and settings relating to the operation of the therapy unit 108. The control circuit 132 may receive such inputs from the user interface 128 and control the therapy unit 108 in accordance with the inputs.

[0043] The instillation pump 130 is configured to cause instillation fluid to be transported from the instillation fluid source 110 to the wound space 120 via second tubing 112. The instillation pump 130 may be controllable by the control circuit 132 to provide a desired amount of the instillation fluid to the wound space 120, provide instillation fluid to the wound space 120 at a desired rate, prevent instillation fluid from flowing to the wound space 120, or otherwise control the flow of instillation fluid to the wound space 120. The instillation pump may include a peristaltic pump or some other type of pump.

[0044] The first valve 125 and second valve 126 are controllable between an open position and a closed position. As shown in FIG. 3, the first valve 125 and the second valve 126 are located at an interior of the therapy unit 108. The second valve 126 is also shown as communicable with the one or more outer lumens 118 of the first tubing 106. Although FIG. 3 illustrates system 100 having a two valves (i.e., first valve 125 and second valve 126), it is understood that any number of valves may be included in system 100. For example, system 100 may include two valves (disposed in a series configuration) operating in a chatter configuration (e.g., simultaneously opening and closing, alternatively opening and closing). The first valve 125 and the second valve 126 may also be controllable to allow a controlled rate of airflow therethrough to facilitate determination of a volume of the wound space 120.

[0045] The control circuit 132 is configured to control the operation of the therapy unit 108. For example, as described in detail below, the control circuit 132 is configured to control the pneumatic pump 122 to remove air from the sealed space to establish a negative pressure in the sealed space, control the first valve 125 to provide a controlled leak to the sealed space, receive pressure measurements from the first sensor 123, determine a volume of the wound space 120 based on the pressure measurements, and customize a wound therapy based on the volume of the wound space 120. Although the control circuit 132 is described herein as to determine a volume of the wound space 120, the control circuit 132 may additionally, or alternatively, use the pressure measurements to determine a rate of dwell therapy, a frequency of periodic instillation therapy, or a volume of constant stream instillation. Accordingly, although the system is described herein as applying an instillation fluid, any other fluid (e.g., collagen) may be used.

Method of Making a Wound Dressing

[0046] Referring now to FIG. 4, a method 400 for making a wound dressing (e.g., dressing 102) is shown, according to an exemplary embodiment. Step 402 includes providing drape layer 202.. The drape layer may include one or more fluid communication holes 212 configured to receive a conduit for coupling to a therapy device (e.g., therapy unit 108). In some such embodiments, the step 402 involves engaging the one or more fluid communication holes 212 with a pneumatic conduit (e.g., first tubing 106, second tubing 112).

[0047] Step 404 is shown to involve providing intermediate layer 210. The provided intermediate layer 210 may be configured to be substantially aligned and coextensive with a patient interface layer. In some embodiments, step 404 involves providing intermediate layer 210 structured as an absorbent core. In such embodiments, intermediate layer 210 may include or be formed of a superabsorbent polymer. In other embodiments, step 404 involves providing intermediate layer 210 structured as a manifold layer for use in negative pressure wound therapy (NPWT). In such embodiments, the manifold layer may facilitate a manifolding effect that allows airflow therethrough and facilitates the distribution of negative pressure across the wound bed 114.

[0048] Step 406 is shown to involve providing patient interface layer 208. Providing patient interface layer 208 may involve providing a plurality of openings through the patient interface layer 208. Iln some embodiments, providing patient interface layer 208 involves substantially aligning the patient interface layer 208 with and sizing the patient interface layer 208 to be coextensive with or overlapping the intermediate layer 210.

[0049] Step 408 is shown to involve placing intermediate layer 210 beneath the drape layer 202. In some embodiments, step 408 involves centering the intermediate layer 210 beneath the drape layer 202. In some embodiments, step 408 involves providing intermediate layer 210 as an absorbent core. In such embodiments, the intermediate layer 210 comprises a superabsorbent polymer. In some embodiments, step 408 involves providing intermediate layer 210 as a hydrophilic manifold layer. [0050] Step 410 is shown to involve placing the patient interface layer 208 beneath the intermediate layer 210. In various arrangements, step 410 involves centering the patient interface layer 208 beneath the intermediate layer 210. Providing patient interface layer 208 may involve providing a plurality of openings formed through the patient interface layer 208.

[0051] Step 412 is shown to involve applying adhesive material 204 to at least a portion of the drape layer 202. In some embodiments, the adhesive material 204 is an acrylic adhesive. Applying the adhesive material 204 to the drape layer 202 may involve any application such as depositing, spraying, brushing, or wiping the adhesive material 204 onto the drape layer 202. In some embodiments, applying adhesive material 204 involves disposing the adhesive material 204 proximate an edge of the drape layer 202.

[0052] Step 414 is shown to involve depositing activation layer 206 over at least a portion of the adhesive material 204. In some embodiments, the activation layer 206 may be placed over an entirety of the adhesive material 204. The activation layer 206 may be any desirable dissolvable material such as a hydrophilic polymer.

Method of Applying a Wound Dressing

[0053] Referring now to FIG. 5, a method 500 of applying a wound dressing (e.g., dressing 102) is shown, according to an exemplary embodiment. Step 502 is shown to involve positioning the dressing 102 on a patient. In some embodiments, positioning dressing 102 on a patient involves aligning patient interface layer 208 with wound bed 114. The dressing 102 includes adhesive material 204 disposed on at least a portion of drape layer 202. The dressing 102 further includes an activation layer 206 at least partially covering the adhesive material 204.

[0054] Step 504 is shown to involve applying moisture to an area around a wound. In some embodiments, the moisture may be from perspiration produced by a patient. In various arrangements, applying moisture may involve dressing applier personnel (e.g., a nurse, a doctor) applying moisture via an application tool such as a brush or a towel. For example, a dressing applier may apply moisture to the area around a wound by wiping a moist towel to the area around a wound to moisten the area.

In another example, dressing applier personnel may spray the area around the wound with moisture (e.g. water, saline, etc).

[0055] Step 506 is shown to involve activating the dressing 102 by dissolving the dissolvable material of the activation layer 206. The activation layer 206 may be dissolved upon interfacing of the dissolvable material with the applied moisture. The dissolved material may be evaporated through the drape layer 202 or may be drawn away by an NPWT therapy unit. Dissolving the activation layer 206 exposes the adhesive material 204 to an area around a wound.

[0056] Step 508 is shown to involve adhering the adhesive material 204 to the area around the wound. The adhesive material 204 may adhere to the area around the wound upon exposure of the adhesive material 204 to the area around the wound. The adhesive material 204 may secure a location of the dressing 102 relative to the area around the wound upon adhering to the area around the wound.

Method of Applying Negative Pressure Wound Therapy

[0057] Referring now to FIG. 6, a method 600 for applying a customized negative pressure wound therapy is shown, according to an exemplary embodiment. The method 600 may be carried out by the NPWT system 100 of FIG. 3. Step 602 is shown to involve providing dressing 102 with activation layer 206. Activation layer 206 is disposed on at least a portion of the adhesive material 204.

[0058] Step 604 is shown to involve applying the wound dressing 102 with activation layer 206 to a patient. The dressing 102 may be constructed prior to application of the dressing 102 to the patient as described with reference to method 400. First tubing 106 and/or second tubing 112 may be coupled with dressing 102 via the fluid communication holes 212.

[0059] Step 606 is shown to involve establishing a sealed space defined by the wound space 120, dressing 102, first tubing 106, and the therapy unit 108. The sealed space includes the wound space 120. In other words, the dressing 102 is applied to the wound bed 114 with the drape layer 202 sealed over the wound bed 114 and the intermediate layer 210 (or other layers included in the dressing 102 in various embodiments) to define the wound space 120. First tubing 106 is coupled to the drape layer 202 in fluid communication with the wound space 120 via the fluid communication hole 212. The first tubing 106 is also coupled to the canister 104 in fluid communication with the canister 104 or therapy unit 108.

[0060] Step 608 is shown to involve operating the pneumatic pump 122 to draw a negative pressure in the sealed space. That is, the control circuit 132 provides a control signal to the pneumatic pump 122 that causes the pneumatic pump 122 to remove air from the sealed space. The control circuit 132 may receive pressure measurements from first sensor 123 and cause the pneumatic pump 122 to cease operation when a desired negative pressure is achieved (e.g., -125 mmHG) and/or otherwise control the pneumatic pump 122 based on the pressure measurements to provide a desired negative pressure or pattern of desired negative pressures.

[0061] Step 610 is shown to involve repeatedly opening and closing (e.g., cycling) the first valve 125 to allow a controlled rate of airflow therethrough. The control circuit 132 may provide a control signal to the first valve 125 that causes the first valve 125 to repeatedly open and close. For example, in an embodiment where the first valve 125 is a solenoid valve, the control circuit 132 provides a voltage pattern to the first valve 125. That is, the control circuit 132 may repeatedly alternate a voltage differential across between a positive lead and a negative lead between approximately zero volts and a non-zero voltage (e.g., approximately five volts). For example, the voltage pattern may include a step function that repeatedly steps between approximately zero voltage and the non-zero voltage.

[0062] Step 612 is shown to involve measuring the pressure in the sealed space as the negative pressure in the sealed space decays towards ambient pressure (i.e., approaches approximately atmospheric pressure). The controlled airflow through the first valve 125 allows air to enter the sealed space and causes the pressure in the sealed space to decay towards ambient pressure. The first sensor 123 may measure the pressure in the sealed space and provide the pressure measurements to the control circuit 132. The control circuit 132 may record (store, save) the pressure measurements.

In some embodiments, the control circuit 132 may collect the pressure measurements to form a pressure decay curve.

[0063] Step 614 is shown to involve determining the volume of the wound space 120 based on the pressure measurements. For example, based on the known controlled rate of airflow through the first valve 125 and the measured pressure decay curve, the volume of the sealed space may be determined. The volume of the wound space may then be determined by removing a volume of the canister and tube from the total volume of the sealed space. In some cases, one or more additional valves, sensors, etc. are include to facilitate generation and collection of data for use in wound size determination. Various methods for calculating wound size are described in U.S. Patent Application No. 62/802,034 filed February 6, 2019, incorporated by reference herein in its entirety.

[0064] Step 616 is shown to involve displaying, on the user interface 128, the wound size (e.g., the volume of the wound space 120) and/or a message relating thereto. For example, the control circuit 132 may cause a graphical user interface that includes the wound size to be displayed on a screen of the user interface 128. As another example, the control circuit 132 may determine one or more warnings, progress reports, or other wound-related messages based on the wound size and control the user interface 128 to display the warning, report, or other message. For example, user interface 128 may display a graphical representation of change in the volume of the wound space over time.

[0065] Step 618 is shown to involve customizing a wound therapy based on the volume of the wound space 120. In some embodiments, the control circuit 132 automatically customizes a wound therapy based on the determined volume of the wound space 120. In other embodiments, a user is facilitated in customizing a wound therapy based on the volume of the wound space 120 based on information displayed on the user interface 128.

[0066] In the example shown, the control circuit 132 automatically customizes instillation by automatically determining an amount of instillation fluid to be supplied to the wound space 120 based on the determined volume of the wound space 120. For example, the control circuit 132 may multiply the determined volume of the wound space 120 by a scaling factor to determine the amount of instillation fluid to be supplied to the wound space 120. As another example, the control circuit 132 may determine the amount of instillation to be supplied as equal to the volume of the wound space 120. Various calculations are possible for various applications, wound types, instillation fluid types, patient and/or caregiver preferences, etc.

[0067] Step 620 is shown to involve providing the customized wound therapy. For example, the control circuit 132 may control the instillation pump 130 to provide the determined amount of instillation fluid from the instillation fluid source 110 to the wound space 120. Instillation therapy may thereby be tailored to meet the needs of the healing wound in real time. Various other customized therapies are possible in various embodiments.

Configuration of Exemplary Embodiments

[0068] As utilized herein, the terms “approximately,” “about,” “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 should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims. [0069] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[0070] The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

[0071] References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure. Although the figures show a specific order of method steps, the order of the steps may differ from what is depicted. Also two or more steps can be performed concurrently or with partial concurrence. Such variation will depend on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations could be accomplished with standard programming techniques with rule based logic and other logic to accomplish the various connection steps, calculation steps, processing steps, comparison steps, and decision steps.

[0072] The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements can be reversed or otherwise varied and the nature or number of discrete elements or positions can be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps can be varied or re sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

Claims

WHAT IS CLAIMED:

1. A negative pressure wound therapy system, comprising: a dressing configured to be sealed over a wound, the dressing comprising: a drape layer comprising an adhesive material disposed on the drape layer; and an activation layer disposed on the drape layer and comprising a dissolvable material; a conduit coupled to the dressing; and a negative pressure therapy unit coupled to the conduit.

2. The system of claim 1, wherein the dissolvable material dissolves and exposes the adhesive material upon activation of the activation layer.

3. The system of claim 1, wherein the activation layer further comprises a medicinal material.

4. The system of claim 1, wherein the activation layer comprises at least one opening formed therethrough and configured to permit passage of the adhesive material to an area around the wound.

5. The system of claim 4, wherein the passage of the adhesive material through the at least one opening provides an initial bond configured to adhere the dressing in a desired position until the activation layer is activated.

6. The system of claim 1, wherein a thickness of the activation layer is variable to provide a variable activation period.

7. The system of claim 1, wherein the drape layer further comprises an opening providing an interface with the conduit.

8. A dressing, comprising: a patient interface layer having openings formed therethrough; an intermediate layer comprising at least one of an absorbent layer and a manifold layer disposed atop the patient interface layer; a drape layer disposed above the intermediate layer and comprising an adhesive material disposed at least partially on the drape layer; and an activation layer disposed on at least a portion of the adhesive material and comprising a dissolvable material

9. The dressing of claim 8, wherein the dissolvable material dissolves upon exposure to perspiration and exposes the adhesive material upon activation of the activation layer;

10. The dressing of claim 8, wherein the activation layer further comprises a medicinal material.

11. The dressing of claim 8, wherein the activation layer comprises at least one opening formed therethrough and configured to permit passage of the adhesive material to an area around the wound.

12. The dressing of claim 11, wherein the passage of the adhesive material through the at least one opening provides an initial bond configured to at least partially adhere the dressing in a desired position until the activation layer is activated.

13. The dressing of claim 8, wherein a thickness of the activation layer is variable a first reduced thickness to provide a reduce activation period and a second greater thickness to provide a greater activation period..

14. The dressing of claim 8, wherein the drape layer comprises an opening providing an interface with a conduit.

15. A method of making a wound dressing, comprising: providing a drape layer; applying an adhesive material to at least a portion of the drape layer; and depositing a dissolvable material over at least a portion of the adhesive material.

16. The method of claim 15, further comprising providing the drape layer having at least one opening for coupling to a negative pressure therapy device.

17. The method of claim 15, further comprising providing an absorbent core comprising an absorbent material and placing the absorbent core beneath the drape layer.

18. The method of claim 15, further comprising providing the dissolvable material with a medicinal material.

19. A method of applying a wound dressing, comprising: positioning the wound dressing on a patient, the wound dressing having an adhesive material at least partially covered with a dissolvable material; and activating the wound dressing by dissolving the dissolvable material to the covered adhesive material.

20. The method of claim 19, further comprising applying moisture to initiate activation of the dissolvable material.