HK1154477A - Super-absorbent, reduced-pressure wound dressing and systems - Google Patents

Abstract

A super-absorbent dressing assembly for use with a reduced-pressure wound treatment system includes a breathable, fluid restricted dry layer for placement against a wound, a super- absorbent layer, and a non-breathable layer, and a drape extending over the non-breathable layer. A reduced-pressure interface is available to fluidly couple the super-absorbent layer to a reduced-pressure subsystem. The super-absorbent dressing assembly preferably supplies a compressive force when placed under reduced pressure. A reduced-pressure treatment system uses a super-absorbent bolster to treat wounds, e.g., linear wounds.

Description

Super absorbent reduced pressure wound dressing and system

RELATED APPLICATIONS

In accordance with title 119 (e) of the american code, volume 35, the present invention claims the benefit of the compilation of the following applications: U.S. provisional patent application serial No. 61/057,807 entitled "Reduced-pressure scientific round Treatment System," filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,798, entitled "addressing assembly for Using Reduce Pressure", filed 30.5.2008; U.S. provisional patent application serial No. 61/057,808 entitled "See-Through, Reduced-Pressure addressing", filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,802 entitled "Reduced-Pressure drying Assembly For use application a cloning Force", filed 30.5.2008; U.S. provisional patent application serial No. 61/057,803, entitled "Reduced-Pressure, Linear-round treatment system," filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,800, entitled "Reduced-Pressure, Compression System and Apparatus for use on current Body Part", filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,797, entitled "Reduced-Pressure, Compression System and apparatus for use on Breast Tissue", filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,805, entitled "Super-Absorbent, Reduced-Pressure wounddriving and System," filed on 30.5.2008; U.S. provisional patent application serial No. 61/057,810, entitled "Reduced-Pressure, Compression System and apparatus for use on a Joint", filed on 30.5.2008; U.S. provisional patent application serial No. 61/121,362, entitled "Reduced-Pressure wooden flow System employing an isolatropic drain", filed on 10.12.2008; US provisional patent application serial No. 61/144,067, entitled "Reduced-Pressure, Compression System and apparatus for use on a Joint", filed 12.1.2009. All of these provisional applications are hereby incorporated by reference for all purposes.

Background

The present invention relates generally to medical systems, and more particularly to a super absorbent reduced pressure wound dressing and system suitable for use on wounds such as surgical wounds.

Physicians around the world perform millions of surgical procedures each year. Many procedures are performed as open procedures, and more procedures are performed using minimally invasive procedures, such as endoscopic, arthroscopic, and laparoscopic procedures. As an example, the american society for aesthetic plastic surgery reports over 450,000 liposuction procedures in the united states in 2007.

The surgical procedure involves a significant wound, such as an incision, in the epidermis and associated tissue. In many instances, at the end of the procedure, the incision is closed using a mechanical device such as a staple or suture or closed using an adhesive. Thereafter, the wound is usually covered with only a dry, sterile bandage. Of course, it is not usually just at the epidermis that there is a rupture.

For many surgical procedures, particularly those performed with minimally invasive techniques, a significant amount of the disruption or injury is below the epidermis or at the subcutaneous level. As again an example, in one type of liposuction procedure, after introducing tumescent fluid (saline, mild analgesic and epinephrine), the surgeon will use a trocar and cannula with suction to remove the fat area. In doing so, it is often seen that subcutaneous voids and other tissue defects are formed at tissue sites remote from the incision (through which the cannula is placed) or other incision (through which the device is placed). The damaged tissue will require time and care to heal and cause a number of potential complications and risks, including edema, seroma, hematoma, further bruising, and ecchymosis, to name a few.

To promote healing after many surgical procedures, such as liposuction, a securely fitting wrap or resilient compression garment may be used on the patient for weeks, depending on the body part involved. These devices are sometimes uncomfortable, may apply compression in an uneven manner and may be laborious to remove and put on. Furthermore, due to edema, a large number of different compression garments may be required for a single patient. It is desirable to address some or all of the deficiencies of post-operative wound care at incisions and damaged subcutaneous tissue.

Brief summary

The illustrative embodiments herein may be used with wounds or irregular tissue, including regional wounds and linear wounds. "Linear wound" generally refers to a laceration or incision that is in a straight line. According to an illustrative embodiment, a dressing assembly for use with a reduced pressure treatment system includes a breathable, fluid-restricted desiccant layer for placement against a wound on a patient and having a first surface and an inwardly facing second surface. The dressing assembly also includes a super absorbent layer having a first surface and an inwardly facing second surface. An inwardly facing second surface of the super absorbent layer is disposed adjacent the first surface of the air permeable dry layer. The dressing assembly also includes a gas-impermeable layer having a first surface and an inwardly facing second surface. An inwardly facing second surface of the air impermeable layer is disposed adjacent the first surface of the superabsorbent layer.

According to one illustrative embodiment, a reduced pressure treatment system for treating a wound includes a super-absorbent bolster for placement on the epidermis of a patient and substantially sized to cover the wound. The superabsorbent bolster is operable to deliver (mangiferd) reduced pressure. The reduced-pressure treatment system also includes a sealing subsystem for providing a fluid seal between the superabsorbent dressing bolster and the patient and a reduced-pressure subsystem for delivering reduced pressure to the sealing subsystem. The sealing subsystem and the reduced-pressure subsystem are operable to deliver reduced pressure to the wound. The superabsorbent dressing bolster, the sealing subsystem, and the reduced-pressure subsystem are operable to generate a compressive force.

According to one illustrative embodiment, a system for assisting in the healing of a wound on a patient includes a superabsorbent bolster assembly for placement over a wound of a patient, a sealing subsystem for providing a fluid seal over the superabsorbent bolster assembly and the patient, and a reduced-pressure subsystem for delivering reduced pressure to the sealing subsystem. The superabsorbent bolster, the sealing subsystem, and the reduced-pressure subsystem are operable to deliver reduced pressure to the wound and remove exudate from the wound. The superabsorbent bolster may be operable to hold more than 250 milliliters of fluid while presenting a dry, inward-facing surface. The superabsorbent bolster assembly includes an air permeable, fluid restricted dry layer having a first surface and an inwardly facing second surface and a superabsorbent layer having a first surface and an inwardly facing second surface. An inwardly facing second surface of the super absorbent layer is disposed adjacent the first surface of the air permeable dry layer.

Other objects, features, and advantages of the illustrative embodiments will become apparent with reference to the drawings and detailed description that follow.

Brief description of the drawings

A more complete understanding of the present invention may be derived by referring to the following detailed description when considered in connection with the figures.

FIG. 1 is a schematic cross-section (with a portion shown in elevation) of an illustrative embodiment of a reduced pressure treatment system for treating a wound;

FIG. 2 is an exploded schematic cross-section of an illustrative embodiment of a dressing assembly for use with a reduced-pressure wound treatment system;

FIG. 3 is a schematic top view of a portion of an illustrative embodiment of a dressing assembly for use with a reduced-pressure wound treatment system; and

figure 4 is a schematic top view of a portion of another illustrative embodiment of a dressing assembly for use with a reduced-pressure wound-treatment system.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the present invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

Referring to fig. 1, an illustrative embodiment of a reduced pressure treatment system 10 for treating a wound, such as a linear wound, is presented. With respect to the system 10, the exudate and fluids are contained by the dressing bolster, to the extent that the portable reduced-pressure source may not require a reservoir. The system 10 may generate a compressive force that may be applied relative to a portion of a patient and may be controlled in real time. The system 10 may be used for linear wounds 12 (e.g., incisions), regional wounds, grafts, or subcutaneous voids. In addition, when applied, the system 10 may help stabilize or fix tissue, enhance the tensile strength of the wound, compress subcutaneous tissue to help reduce dead space, isolate the wound from external sources of infection, or enhance perfusion. The tensile strength of a wound means the strength of the wound when a force attempts to pull or open the wound. As used herein, "or" does not require mutual exclusivity unless otherwise paid for.

The reduced pressure treatment system 10 is shown in the area of a linear wound 12, the linear wound 12 being an incision through the epidermis 14 and dermis 16 and into the hypodermis or subcutaneous tissue 18. Subcutaneous tissue 18 may include a variety of tissue types, such as adipose tissue or muscle. The damaged subcutaneous tissue 20 is shown extending from the linear wound 12 and in this example includes a subcutaneous defect, dead space or void 22. The damaged subcutaneous tissue 20 is typically caused by a surgical procedure such as liposuction. The damaged subcutaneous tissue 20 may include voids (such as void 22), open spaces, and various defects that may be troublesome for a number of reasons such as allowing for increased fluid that may lead to edema.

The linear wound 12 may be closed using any closure device, such as staples, sutures, or adhesives, but is shown in this embodiment with sutures 13. The reduced-pressure treatment system 10 is used to treat a linear wound, such as linear wound 12, in this example, linear wound 12 is an incision. The reduced pressure treatment system may also be used to treat subcutaneous tissue 20, a regional wound, or a graft.

The reduced-pressure treatment system 10 includes a superabsorbent dressing assembly 30, the superabsorbent dressing assembly 30 including a superabsorbent dressing bolster 31; a sealing subsystem 60; and a reduced-pressure subsystem 80. When reduced pressure is supplied to the superabsorbent dressing bolster 31, the superabsorbent dressing bolster 31 distributes the reduced pressure to the linear wound 12, generates a compressive force 24, removes fluids, such as exudate, from the linear wound 12, and contains (or stores) substantially all of the removed fluids. The reduced-pressure system 10 is operable to deliver reduced pressure to a linear wound 12 effected at the level of subcutaneous tissue 22 and to help approximate-concentrate together-tissue in the area and to help remove any air or any other fluid.

The superabsorbent dressing assembly 30 includes a superabsorbent bolster 31 having a superabsorbent layer 32, the superabsorbent layer 32 having a first surface 34 and an inwardly facing second surface 36; an access layer 38 (or fluid access layer), the access layer 38 having a first surface 40 and an inwardly facing second surface 42, and which may be a breathable, fluid-restricted, dry layer for placement against a linear wound 12; and a top layer 44, the top layer 44 having a first surface 46 and an inwardly facing second surface 48, and which may be a gas impermeable layer. The superabsorbent dressing bolster 31 is sized and formed to extend substantially beyond the linear wound 12, and if used in an area application, the superabsorbent dressing bolster 31 is sized to substantially match the estimated area of the damaged subcutaneous tissue 20, although larger or smaller sizes may be used in different applications. The super absorbent layer 32 is further described below.

As used herein, "breathable" means gas permeable. The gas permeable, fluid restricted desiccant layer allows gas to permeate and restrict fluid, as will be described. A breathable, fluid-restricted, dry layer is "fluid-restricted" in the sense that it allows fluid to enter, e.g., exudate from a wound may pass through the layer, but liquid generally does not flow in other directions. This means that the bottom surface of the gas permeable, fluid restricted desiccant layer remains dry to contact. The breathable fluid restricted dryness layer is similar to that of a typical disposable diaper placed against the skin of an infant.

The super absorbent dressing bolster 31 is operable to distribute reduced pressure to the linear wound 12 and generate forces. As used herein, the term "manifold" generally refers to a substance or structure provided to assist in applying reduced pressure to, delivering fluids to, or removing fluids from a tissue site. The manifold generally includes a plurality of flow channels or pathways interconnected to improve distribution of fluid provided to or removed from the tissue region surrounding the manifold.

The sealing subsystem 60 includes a drape (flap) 62 or sealing member. The drape 62 may be any material that provides a fluid seal, such as an elastomeric material. By "fluid seal" or "seal" is meant a seal sufficient to maintain reduced pressure at a desired location given the particular reduced-pressure subsystem involved. "elastic" means having the properties of an elastomer. Elasticity generally refers to a polymeric material having rubber-like properties. More specifically, most elastomers have an elongation greater than 100% and a significant amount of resilience. The resiliency of a material refers to the ability of the material to recover from elastic deformation. Examples of elastomers may include, but are not limited to, natural rubber, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene diene monomer, chlorosulfonated polyethylene, polysulfide rubber, polyurethane, EVA film, copolyester, and silicone. Specific examples of drape materials include silicone drapes, 3MA drape, an acrylic drape, such as one available from Avery Dennison, or a incise drape.

The drape 62 may be attached to the superabsorbent dressing bolster 31 and in particular to the first surface 46 of the top layer 44. The connection can be made in a number of ways. The drape 62 and the top layer 44 may be attached using an adhesive, such as by an acrylic adhesive, a silicone adhesive, a hydrogel, a hydrocolloid, or the like. The drape 62 and top layer 44 may be bonded by thermal bonding, ultrasonic bonding, radio frequency bonding, and the like. The connections may be made more thoroughly or completely in a lattice (pattern) fashion. Structural members may be added to the combination to make the drape 62 anisotropic in the desired direction, i.e., to create an anisotropic drape material. The anisotropic drape material assists the dressing assembly 30 to move primarily in a given direction, i.e., only about a certain axis or axes.

In the embodiment of fig. 1, the drape 62 is sized to extend beyond the peripheral edge 39 of the superabsorbent dressing bolster 31 and thereby form a drape extension 64. The drape extension 64 has a first surface 66 and an inwardly facing second surface 68. The drape 62 may be sealed against the patient's epidermis 14 using a sealing device 69 for providing a fluid seal, which allows reduced pressure to be maintained by the reduced-pressure subsystem 80. The sealing device 69 may take many forms, such as an adhesive, a sealing tape 70, or a drape tape or strip, a double-sided drape tape, a paste, a hydrocolloid, a hydrogel, or other sealing means. If the tape 70 is used, the tape 70 may be formed of the same material as the drape 62 with the pressure sensitive adhesive pre-applied. In another embodiment, a pressure sensitive adhesive may be applied on the second surface 68 of the drape extension 64. The adhesive provides a generally fluid seal between the drape 62 and the patient's epidermis 14. The adhesive may have a removable strip covering the pressure sensitive adhesive before the drape 62 is secured to the patient. When the tape 70 is used, the tape 70 is applied over the extension 64 to provide a fluid seal.

The reduced-pressure subsystem 80 includes a reduced-pressure source 82, which may take many different embodiments that provide reduced pressure as part of the reduced-pressure treatment system 10. The reduced-pressure source 82 may be any device for supplying reduced pressure, such as a vacuum pump, wall suction, or other source. While the amount and nature of reduced pressure applied to the tissue site will generally vary depending on the application, the reduced pressure will generally be between-5 mm Hg to-500 mm Hg, and more generally between-100 mm Hg to-300 mm Hg. In some cases a pressure of-200 mm Hg may be used.

As used herein, the term "reduced pressure" generally refers to a pressure that is less than the ambient pressure at the tissue site being treated. In most cases, this reduced pressure will be less than the atmospheric pressure at the location of the patient. Alternatively, the reduced pressure may be less than the hydrostatic pressure at the tissue site. Unless otherwise indicated, the pressure values specified herein are gauge pressures. The delivered reduced pressure may be constant or variable (uniform or random) and may be delivered continuously or intermittently. Although the terms "vacuum" and "negative pressure" may be used to describe the pressure applied to the tissue site, the actual pressure applied to the tissue site may be greater than the pressure typically associated with a complete vacuum. Consistent with the use herein, an increase in reduced or vacuum pressure generally refers to a relative decrease in absolute pressure.

To maximize patient mobility and comfort, reduced pressure source 82 may be a battery-powered, single-use, reduced pressure generator or treatment unit. Such a reduced pressure source 82 facilitates application in an operating room and provides flexibility and convenience to the patient during the rehabilitation phase. Other reduced pressure sources may be utilized, such as those available from KCI of San Antonio, TexasA therapy unit, or a wall-mounted inhalation unit. The reduced pressure source may also be provided by a portable mechanical device, such as a piston within a tube, depending on how much leakage exists using the fluid seal between the dressing bolster and the epidermis.

The superabsorbent nature of the superabsorbent dressing bolster 31 allows for the possibility of utilizing a reduced pressure source that does not require a remote fluid storage tank because the superabsorbent dressing bolster 31 effectively stores fluid. The super absorbent layer 32 may contain 300 milliliters of fluid or more. At the same time, the intake layer 38 keeps the fluid away from the patient's epidermis 14 so that maceration may be avoided. The reduced pressure source 82 is shown with a battery compartment 84. An intervening membrane filter, such as a hydrophobic or oleophobic filter, may be interspersed between the reduced-pressure delivery conduit or pipe 90 and the reduced-pressure source 82.

The reduced pressure generated by the reduced-pressure source 82 is communicated through the reduced-pressure conduit 90 to a reduced-pressure interface 92, which reduced-pressure interface 92 may be an elbow port 94. In one embodiment, elbow port 94 is obtained from KCI of San Antonio, TexasA process port. The reduced-pressure interface 92 allows reduced pressure to be communicated to the sealing subsystem 60 and realized within the interior portion of the sealing subsystem 60. In this particular embodiment, the reduced-pressure interface 92 extends through the drape 62 and into the super-absorbent dressing bolster 31.

In operation, reduced pressure treatment system 10 may be applied in an operating room after a surgical procedure is performed on a patient or elsewhere. The second surface 42 of the intake layer 38 of the superabsorbent dressing bolster 31 will be placed over the linear wound 12 relative to the patient's epidermis 14. The dressing assembly 30 may be sized for the general applications involved in the procedures performed by the health care provider. The dressing assembly 30 may be sized, shaped, and configured to work with different tissue applications, such as abdomen, chest, thighs, buttocks, and the like.

If the drape 62 has not been attached to the superabsorbent dressing bolster 31, the drape 62 is placed over the first surface 46 of the top layer 44 and the peripheral edge 39 of the superabsorbent dressing bolster 31, with more than a portion extending beyond the peripheral edge 39 to form a drape extension 64. The drape extension 64 may then be adhered using tape 70 or an adhesive for forming a fluid seal between the drape 62 and the patient's epidermis 14. The fluid seal need only be sufficient to allow the reduced pressure treatment system 10 to maintain reduced pressure over the treatment area or tissue site for a desired treatment time. The reduced-pressure interface 92 is applied even though it is not yet installed. The reduced-pressure delivery conduit 90 is fluidly connected to the reduced-pressure source 82 and a reduced-pressure interface 92. The reduced pressure source 82 may then be activated and reduced pressure delivered to the superabsorbent dressing bolster 31.

When the pressure is reduced at the super-absorbent dressing bolster 31, the reduced pressure is further still transmitted through the super-absorbent dressing bolster 31 such that the reduced pressure is experienced at the patient's epidermis 14 proximate the linear wound 12. Reduced pressure may be achieved through the linear wound 12 and within the subcutaneous tissue 20, at least during the early stages of the healing process, and if so, the reduced pressure helps close defects (if any) such as subcutaneous voids 22 and generally provides stability to the treatment area. The reduced pressure delivered to the superabsorbent dressing bolster 31 also creates a compressive force 24 that again provides stability and may enhance tensile strength, etc. The compressive force 24 may be greater than just at the top of the epidermis 14. The compressive force may extend deeper down and may be felt at the level of the subcutaneous tissue 20.

During treatment care is taken to avoid skin irritation, such as blistering of the patient's epidermis 14 due to secondary shear, secondary strain (strain), or other effects. To help avoid skin irritation, the peripheral edge 39 may be shaped or angled, or an inner layer may be added between the superabsorbent dressing bolster 31 and the patient's epidermis 14.

Referring now to fig. 2, an exploded schematic cross-section of a portion of a superabsorbent dressing assembly 130 for use with a reduced-pressure wound therapy system is shown. The superabsorbent dressing assembly 130 is similar in most respects to the superabsorbent dressing assembly 30 of fig. 1, but the superabsorbent dressing assembly 130 is shown without a drape extending over the superabsorbent dressing assembly 130. The superabsorbent dressing assembly 130 can include a number of layers, but is shown in this illustrative embodiment as having a superabsorbent dressing bolster 131 that includes three major layers: a super absorbent layer 132, an intake layer 138, and a topsheet 144.

The entry layer 138 has a first surface 140 and an inwardly facing second surface 142. The entry layer 138 is intended to allow fluid to exit the linear wound 112 on the patient's epidermis 114 and pass through the entry layer 138 without remaining on the epidermis 114. In other words, the entry layer 138 functions to effectively allow flow in only one direction. This unidirectional action helps to avoid maceration of the skin 114. The intake layer 138 also helps to deliver or distribute the reduced pressure tube to the linear wound 112. The intake layer 138 may be described as a breathable, dry layer. Many materials may be used for the intake layer 138, such as hydrophilic nonwoven materials.

The top layer 144 has a first surface 146 and an inwardly facing second surface 148. The top layer 144 can be a gas impermeable layer. The top layer 144 may have an aperture 149 formed through the top layer 144 to receive reduced pressure fluidly connected to a reduced pressure source. The top layer 144 helps provide a seal over the superabsorbent layer 132. Many materials may be used for the top layer 144, such as polyethylene film, which will prevent fluid from leaking out. In an alternative embodiment, the top layer 144 can be omitted and the drape alone used to confine fluid within the superabsorbent dressing assembly 130.

An additional interface gas permeable layer 194 may be added to the first surface 146 of the top layer 144 to act as a filter. The interface gas permeable layer 194 covers the aperture 149. The connector breathable layer 194 allows for the transmission of reduced pressure and prevents portions of the superabsorbent layer 132 from entering a reduced-pressure connector, such as the reduced-pressure connector 92 of fig. 1, disposed on top of the superabsorbent dressing assembly 130.

The super absorbent layer 132 has a first surface 134 and an inwardly facing second surface 136. The super absorbent layer 132 helps to deliver reduced pressure to the entry layer 138 and on to the linear wound 112. The super absorbent layer 132 is operable to contain a relatively large amount of fluid and to help function as a dressing bolster for generating compressive forces (e.g., force 24 in fig. 1).

The superabsorbent layer 32 (fig. 1) and superabsorbent layer 132 may be formed from superabsorbent polymers (SAPs) of the type commonly referred to as "hydrogels," superabsorbents, "or" hydrocolloids. Superabsorbent spheres may also be used which will deliver reduced pressure until the superabsorbent spheres become saturated. To allow reduced pressure to be used without a remote canister or with a relatively small remote canister in a human patient, it is desirable to have the super absorbent layer 132 operable to contain at least 300 milliliters of fluid with many surgical applications. In some applications, it may also be desirable to provide a superabsorbent material in the reduced-pressure delivery conduit (e.g., 90 in FIG. 1) between the superabsorbent dressing 132 and the reduced-pressure source to further contain the fluid.

When fluid is added to the superabsorbent layer 132, the dressing bolster 131 becomes stiffer and under reduced pressure, which results in an increased compressive force, such as force 24 in fig. 1. The fluid may be in the form of exudate or other fluid from the linear wound 112, or may be a supplemental fluid, such as saline, intentionally added by injection or otherwise.

Referring now to fig. 3, a superabsorbent dressing assembly 230 may be formed with a reduced-pressure interface 292 for delivering reduced pressure and an injection port 233. The injection port 233 facilitates fluid injection into the superabsorbent layer of the superabsorbent dressing assembly 230.

Referring now to fig. 4, the superabsorbent dressing assembly 330 may have a first interface 392 or a reduced-pressure interface for delivering reduced pressure to the superabsorbent layer, and may also include a second interface 335 or a fluid-delivery interface for delivering a fluid, such as saline, to the superabsorbent layer.

Whether through the injection port 233 (fig. 3) or the second interface 335 (fig. 4) or otherwise, a fluid may be added to the superabsorbent layer to enhance the stiffness of the superabsorbent layer, and this provides a liquid controlled bolster. The addition of the liquid controls the hardness, which in turn can control the compressive force generated under the action of reduced pressure. If fluid is supplied by a bleeding (e.g., bleeding) wound, the additional compressive force created by the additional fluid-exudate helps make the dressing somewhat self-adjusting or self-regulating. This is particularly useful in wound treatment on a battlefield. The amount of compression produced may also be affected by the elasticity of the drape; the more it is stretchable, the less compressive force will be generated. A transducer and controller may be provided which facilitates measurement of the compression force and enables adjustment of the amount of fluid supplied through the second interface 335 (or removed through the first interface 392) to adjust the compression within a desired level or desired parameters.

According to another illustrative embodiment, a method of manufacturing a dressing assembly for use with a reduced-pressure wound therapy system includes the steps of: forming a breathable, fluid-restricted, dry layer for placement against a wound and having a first surface and an inwardly facing second surface; disposing a super absorbent layer having a first surface and an inwardly facing second surface adjacent to the air permeable dry layer; an air impermeable layer having a first surface and an inwardly facing second surface is disposed adjacent the first surface of the superabsorbent layer. The method of manufacturing further includes placing a drape over the first surface of the gas-impermeable layer; and fluidly connecting the reduced-pressure interface to the super-absorbent layer.

Although the present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments, it should be understood that various changes, substitutions, permutations and alterations can be made herein without departing from the scope of the invention as defined by the appended claims. It will be appreciated that any feature described in connection with any one embodiment may also be applied to any other embodiment.

Claims (19)

1. A dressing assembly for use with a reduced-pressure treatment system, the dressing assembly comprising:

a breathable, fluid-restricted, dry layer for placement against a wound on a patient and having a first surface and an inwardly facing second surface;

a super absorbent layer having a first surface and an inwardly facing second surface, the inwardly facing second surface of the super absorbent layer disposed adjacent the first surface of the air permeable dry layer; and

an air impermeable layer having a first surface and an inwardly facing second surface, the inwardly facing second surface of the air impermeable layer disposed adjacent the first surface of the super absorbent layer.

2. The dressing assembly of claim 1, further comprising a drape extending over the first surface of the air-impermeable layer and a reduced-pressure interface fluidly connected to the super-absorbent layer and operable with a sealing subsystem to receive reduced pressure.

3. The dressing assembly of claim 1, further comprising a drape extension formed from a portion of the drape extending beyond peripheral edges of the gas-permeable, fluid-restricted dry layer, the super-absorbent layer, and the gas-impermeable layer.

4. The dressing assembly of claim 1, further comprising a drape extension formed from a portion of the drape extending beyond peripheral edges of the gas-permeable, fluid-restricted dry layer, the super-absorbent layer, and the gas-impermeable layer; and further comprising a sealing arrangement for outwardly sealing the drape to the patient's epidermis.

5. The dressing assembly of claim 1, wherein the superabsorbent layer is operable to contain at least 300 milliliters of fluid.

6. A reduced-pressure treatment system for treating a wound, the system comprising:

a super absorbent bolster for placement on the epidermis of a patient and substantially sized to cover the wound, the super absorbent bolster operable to deliver reduced pressure;

a sealing subsystem for providing a fluid seal between the superabsorbent dressing bolster and a patient;

a reduced-pressure subsystem for delivering reduced pressure to the sealing subsystem;

wherein the sealing subsystem and the reduced-pressure subsystem are operable to deliver reduced pressure to the wound; and

wherein the superabsorbent dressing bolster, the sealing subsystem, and the reduced-pressure subsystem are operable to generate a compressive force.

7. The system of claim 6, wherein the superabsorbent dressing bolster comprises:

an air permeable, fluid confined desiccant layer having a first surface and an inwardly facing second surface;

a super absorbent layer having a first surface and a second surface, the second, inward facing surface of the super absorbent layer being disposed adjacent the first surface of the air permeable dry layer; and

an air impermeable layer having a first surface and a second surface, the second, inward facing surface of the air impermeable layer being disposed adjacent the first surface of the superabsorbent layer.

8. The system of claim 6, wherein the superabsorbent dressing bolster comprises: a superabsorbent material operable under reduced pressure to generate a compressive force that is greater when a fluid is added to the superabsorbent material.

9. The system of claim 6, wherein the superabsorbent dressing bolster comprises:

a superabsorbent material having a first surface and an inwardly facing second surface;

a breathable drying layer having a first surface and a second surface; and

wherein the second surface of the superabsorbent material is at least partially attached to the first surface of the air-permeable drying layer.

10. The system of claim 6, wherein the superabsorbent dressing bolster comprises:

a superabsorbent material having a first surface and an inwardly facing second surface and being operable to increase in hardness with the addition of a fluid;

a breathable drying layer having a first surface and an inwardly facing second surface;

an air impermeable layer having a first surface and an inwardly facing second surface; and

wherein the second, inwardly facing surface of the superabsorbent material is at least partially attached to the first surface of the air-permeable drying layer and the second, inwardly facing surface on the air-impermeable layer and the first surface of the superabsorbent material are at least partially attached.

11. The system of claim 6, wherein the sealing subsystem comprises: a drape extending over the super-absorbent bolster.

12. The system of claim 6, wherein the sealing subsystem comprises:

a drape extending over the super-absorbent bolster; and

a sealing device for providing a fluid seal between the patient's epidermis and the drape.

13. The system of claim 6, wherein the reduced-pressure subsystem comprises:

a reduced-pressure source for providing reduced pressure;

a reduced-pressure interface connected to the sealing subsystem; and

a reduced-pressure delivery conduit for providing a reduced pressure from the reduced-pressure source to the reduced-pressure interface.

14. The system of claim 6, wherein the reduced-pressure subsystem comprises:

a reduced-pressure source operable to provide a variable pressure below ambient pressure;

a reduced-pressure interface connected to the sealing subsystem;

a reduced-pressure delivery conduit for providing a reduced pressure from the reduced-pressure source to the reduced-pressure interface.

15. The system of claim 6, wherein the reduced-pressure subsystem comprises:

a portable reduced-pressure source;

a reduced-pressure interface connected to the sealing subsystem;

a reduced-pressure delivery conduit for providing a reduced pressure from the reduced-pressure source to the reduced-pressure interface; and

wherein the reduced-pressure interface transmits reduced pressure to the sealing subsystem.

16. A system for assisting healing of a wound on a patient, the system comprising:

a super absorbent bolster assembly for placement over a wound of a patient;

a sealing subsystem for providing a fluid seal over the superabsorbent bolster assembly and the patient;

a reduced-pressure subsystem for delivering reduced pressure to the sealing subsystem; and

wherein the super-absorbent bolster, the sealing subsystem, and the reduced-pressure subsystem are operable to deliver reduced pressure to the wound and remove exudate from the wound;

wherein the superabsorbent bolster is operable to hold more than 250 milliliters of fluid while presenting a dry, inwardly facing surface; and

wherein the absorbent bolster assembly comprises:

an air permeable, fluid confined desiccant layer having a first surface and an inwardly facing second surface; and

a super absorbent layer having a first surface and an inwardly facing second surface, the inwardly facing second surface of the super absorbent layer disposed adjacent the first surface of the air permeable dry layer.

17. The system of claim 16, further comprising a reduced-pressure interface coupled on a first surface of the gas-impermeable layer and operable with the sealing subsystem to receive reduced pressure.

18. The system of claim 16, wherein the superabsorbent bolster further comprises an air impermeable layer having a first surface and an inwardly facing second surface, the inwardly facing second surface of the air impermeable layer being disposed adjacent the first surface of the superabsorbent layer.

19. The system of claim 16, further comprising a fluid transfer interface for transferring fluid to the super absorbent layer, the fluid transfer interface connected to the first surface of the air impermeable layer and fluidly connected to the super absorbent layer.